[doc] rearranges Settings & Engines docs for better readability

We have built up detailed documentation of the *settings* and the *engines* over
the past few years.  However, this documentation was still spread over various
chapters and was difficult to navigate in its entirety.

This patch rearranges the Settings & Engines documentation for better
readability.

To review new ordered docs::

   make docs.clean docs.live

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

31 files changed, 833 insertions, 35 deletions

diff --git a/docs/dev/contribution_guide.rst b/docs/dev/contribution_guide.rst
index 0a2f07e40..67133b6b3 100644
--- a/docs/dev/contribution_guide.rst
+++ b/docs/dev/contribution_guide.rst
@@ -4,7 +4,7 @@
 How to contribute
 =================
 
-.. contents:: Contents
+.. contents::
    :depth: 2
    :local:
    :backlinks: entry
diff --git a/docs/dev/engines/demo/demo_offline.rst b/docs/dev/engines/demo/demo_offline.rst
new file mode 100644
index 000000000..1b4cb887f
--- /dev/null
+++ b/docs/dev/engines/demo/demo_offline.rst
@@ -0,0 +1,14 @@
+.. _demo offline engine:
+
+===================
+Demo Offline Engine
+===================
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. automodule:: searx.engines.demo_offline
+  :members:
+
diff --git a/docs/dev/engines/demo/demo_online.rst b/docs/dev/engines/demo/demo_online.rst
new file mode 100644
index 000000000..9b94207f7
--- /dev/null
+++ b/docs/dev/engines/demo/demo_online.rst
@@ -0,0 +1,14 @@
+.. _demo online engine:
+
+==================
+Demo Online Engine
+==================
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. automodule:: searx.engines.demo_online
+  :members:
+
diff --git a/docs/dev/engine_overview.rst b/docs/dev/engines/engine_overview.rst
index 5fd31c01d..8052a8bea 100644
--- a/docs/dev/engine_overview.rst
+++ b/docs/dev/engines/engine_overview.rst
@@ -4,6 +4,11 @@
 Engine Overview
 ===============
 
+.. contents::
+   :depth: 3
+   :local:
+   :backlinks: entry
+
 .. _metasearch-engine: https://en.wikipedia.org/wiki/Metasearch_engine
 
 .. sidebar:: Further reading ..
@@ -11,10 +16,6 @@ Engine Overview
    - :ref:`configured engines`
    - :ref:`settings engine`
 
-.. contents::
-   :depth: 3
-   :backlinks: entry
-
 SearXNG is a metasearch-engine_, so it uses different search engines to provide
 better results.
 
@@ -49,12 +50,12 @@ Engine File
    categories              list        categories, in which the engine is working
    paging                  boolean     support multiple pages
    time_range_support      boolean     support search time range
-   engine_type             str         - ``online`` :ref:`[ref] <demo online engine>` by
+   engine_type             str         - ``online`` :ref:`[ref] <online engines>` by
                                          default, other possibles values are:
                                        - ``offline`` :ref:`[ref] <offline engines>`
-                                       - ``online_dictionary``
-                                       - ``online_currency``
-                                       - ``online_url_search``
+                                       - ``online_dictionary`` :ref:`[ref] <online dictionary>`
+                                       - ``online_currency`` :ref:`[ref] <online currency>`
+                                       - ``online_url_search`` :ref:`[ref] <online url search>`
    ======================= =========== ========================================================
 
 .. _engine settings:
@@ -239,12 +240,18 @@ following parameters can be used to specify a search request:
 .. _engine results:
 .. _engine media types:
 
-Media Types
-===========
+Result Types (``template``)
+===========================
 
 Each result item of an engine can be of different media-types.  Currently the
-following media-types are supported.  To set another media-type as ``default``,
-the parameter ``template`` must be set to the desired type.
+following media-types are supported.  To set another media-type as
+:ref:`template default`, the parameter ``template`` must be set to the desired
+type.
+
+.. _template default:
+
+``default``
+-----------
 
 .. table::  Parameter of the **default** media type:
    :width: 100%
@@ -259,6 +266,11 @@ the parameter ``template`` must be set to the desired type.
    ========================= =====================================================
 
 
+.. _template images:
+
+``images``
+----------
+
 .. table::  Parameter of the **images** media type:
    :width: 100%
 
@@ -277,6 +289,11 @@ the parameter ``template`` must be set to the desired type.
    ========================= =====================================================
 
 
+.. _template videos:
+
+``videos``
+----------
+
 .. table::  Parameter of the **videos** media type:
    :width: 100%
 
@@ -292,6 +309,12 @@ the parameter ``template`` must be set to the desired type.
    thumbnail                 string, url to a small-preview image
    ========================= =====================================================
 
+
+.. _template torrent:
+
+``torrent``
+-----------
+
 .. _magnetlink: https://en.wikipedia.org/wiki/Magnet_URI_scheme
 
 .. table::  Parameter of the **torrent** media type:
@@ -315,6 +338,12 @@ the parameter ``template`` must be set to the desired type.
    torrentfile               string, torrentfile of the result
    ========================= =====================================================
 
+
+.. _template map:
+
+``map``
+-------
+
 .. table::  Parameter of the **map** media type:
    :width: 100%
 
@@ -342,6 +371,12 @@ the parameter ``template`` must be set to the desired type.
    address.country           country of object
    ========================= =====================================================
 
+
+.. _template paper:
+
+``paper``
+---------
+
 .. _BibTeX format: https://www.bibtex.com/g/bibtex-format/
 .. _BibTeX field types: https://en.wikipedia.org/wiki/BibTeX#Field_types
 
@@ -430,3 +465,4 @@ the parameter ``template`` must be set to the desired type.
    * - html_url
      - :py:class:`str`
      - URL to full article, HTML version
+
diff --git a/docs/dev/engines/enginelib.rst b/docs/dev/engines/enginelib.rst
new file mode 100644
index 000000000..34e3250da
--- /dev/null
+++ b/docs/dev/engines/enginelib.rst
@@ -0,0 +1,22 @@
+.. _searx.enginelib:
+
+==============
+Engine Library
+==============
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. automodule:: searx.enginelib
+  :members:
+
+.. _searx.enginelib.traits:
+
+
+Engine traits
+=============
+
+.. automodule:: searx.enginelib.traits
+  :members:
diff --git a/docs/dev/engines/engines.rst b/docs/dev/engines/engines.rst
new file mode 100644
index 000000000..0f2cb1f22
--- /dev/null
+++ b/docs/dev/engines/engines.rst
@@ -0,0 +1,9 @@
+.. _searx.engines loader:
+
+========================
+SearXNG's engines loader
+========================
+
+.. automodule:: searx.engines
+  :members:
+
diff --git a/docs/dev/engines/index.rst b/docs/dev/engines/index.rst
new file mode 100644
index 000000000..ca8f87b3c
--- /dev/null
+++ b/docs/dev/engines/index.rst
@@ -0,0 +1,97 @@
+.. _engine implementations:
+
+======================
+Engine Implementations
+======================
+
+Framework Components
+====================
+
+.. toctree::
+   :maxdepth: 2
+
+   enginelib
+   engines
+   engine_overview
+
+
+Engine Types
+============
+
+The :py:obj:`engine_type <searx.enginelib.Engine.engine_type>` of an engine
+determines which :ref:`search processor <searx.search.processors>` is used by
+the engine.
+
+In this section a list of the enignes that are documented is given, a complete
+list of the engines can be found in the source under: :origin:`searx/engines`.
+
+.. _online engines:
+
+Online Engines
+--------------
+
+.. sidebar:: info
+
+   - :py:obj:`processors.online <searx.search.processors.online>`
+
+.. toctree::
+   :maxdepth: 1
+   :glob:
+
+   demo/demo_online
+   xpath
+   online/*
+
+.. _offline engines:
+
+Offline Engines
+---------------
+
+.. sidebar:: info
+
+   - :py:obj:`processors.offline <searx.search.processors.offline>`
+
+.. toctree::
+   :maxdepth: 1
+   :glob:
+
+   offline_concept
+   demo/demo_offline
+   offline/*
+
+.. _online url search:
+
+Online URL Search
+-----------------
+
+.. sidebar:: info
+
+   - :py:obj:`processors.online_url_search <searx.search.processors.online_url_search>`
+
+.. toctree::
+   :maxdepth: 1
+   :glob:
+
+   online_url_search/*
+
+.. _online currency:
+
+Online Currency
+---------------
+
+.. sidebar:: info
+
+   - :py:obj:`processors.online_currency <searx.search.processors.online_currency>`
+
+*no engine of this type is documented yet / comming soon*
+
+.. _online dictionary:
+
+Online Dictionary
+-----------------
+
+.. sidebar:: info
+
+   - :py:obj:`processors.online_dictionary <searx.search.processors.online_dictionary>`
+
+*no engine of this type is documented yet / comming soon*
diff --git a/docs/dev/engines/offline/command-line-engines.rst b/docs/dev/engines/offline/command-line-engines.rst
new file mode 100644
index 000000000..0a80d698e
--- /dev/null
+++ b/docs/dev/engines/offline/command-line-engines.rst
@@ -0,0 +1,23 @@
+.. _engine command:
+
+====================
+Command Line Engines
+====================
+
+.. sidebar:: info
+
+   - :origin:`command.py <searx/engines/command.py>`
+   - :ref:`offline engines`
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. sidebar:: info
+
+   Initial sponsored by `Search and Discovery Fund
+   <https://nlnet.nl/discovery>`_ of `NLnet Foundation <https://nlnet.nl/>`_.
+
+.. automodule:: searx.engines.command
+  :members:
diff --git a/docs/dev/engines/offline/nosql-engines.rst b/docs/dev/engines/offline/nosql-engines.rst
new file mode 100644
index 000000000..76f5cfb61
--- /dev/null
+++ b/docs/dev/engines/offline/nosql-engines.rst
@@ -0,0 +1,97 @@
+.. _nosql engines:
+
+===============
+NoSQL databases
+===============
+
+.. sidebar:: further read
+
+   - `NoSQL databases <https://en.wikipedia.org/wiki/NoSQL>`_
+   - `redis.io <https://redis.io/>`_
+   - `MongoDB <https://www.mongodb.com>`_
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. sidebar:: info
+
+   Initial sponsored by `Search and Discovery Fund
+   <https://nlnet.nl/discovery>`_ of `NLnet Foundation <https://nlnet.nl/>`_.
+
+The following `NoSQL databases`_ are supported:
+
+- :ref:`engine redis_server`
+- :ref:`engine mongodb`
+
+All of the engines above are just commented out in the :origin:`settings.yml
+<searx/settings.yml>`, as you have to set various options and install
+dependencies before using them.
+
+By default, the engines use the ``key-value`` template for displaying results /
+see :origin:`simple <searx/templates/simple/result_templates/key-value.html>`
+theme.  If you are not satisfied with the original result layout, you can use
+your own template, set ``result_template`` attribute to ``{template_name}`` and
+place the templates at::
+
+  searx/templates/{theme_name}/result_templates/{template_name}
+
+Furthermore, if you do not wish to expose these engines on a public instance, you
+can still add them and limit the access by setting ``tokens`` as described in
+section :ref:`private engines`.
+
+
+Extra Dependencies
+==================
+
+For using :ref:`engine redis_server` or :ref:`engine mongodb` you need to
+install additional packages in Python's Virtual Environment of your SearXNG
+instance.  To switch into the environment (:ref:`searxng-src`) you can use
+:ref:`searxng.sh`::
+
+  $ sudo utils/searxng.sh instance cmd bash
+  (searxng-pyenv)$ pip install ...
+
+
+Configure the engines
+=====================
+
+`NoSQL databases`_ are used for storing arbitrary data without first defining
+their structure.
+
+
+.. _engine redis_server:
+
+Redis Server
+------------
+
+.. _redis: https://github.com/andymccurdy/redis-py#installation
+
+.. sidebar:: info
+
+   - ``pip install`` redis_
+   - redis.io_
+   - :origin:`redis_server.py <searx/engines/redis_server.py>`
+
+.. automodule:: searx.engines.redis_server
+  :members:
+
+
+.. _engine mongodb:
+
+MongoDB
+-------
+
+.. _pymongo: https://github.com/mongodb/mongo-python-driver#installation
+
+.. sidebar:: info
+
+   - ``pip install`` pymongo_
+   - MongoDB_
+   - :origin:`mongodb.py <searx/engines/mongodb.py>`
+
+
+.. automodule:: searx.engines.mongodb
+  :members:
+
diff --git a/docs/dev/engines/offline/search-indexer-engines.rst b/docs/dev/engines/offline/search-indexer-engines.rst
new file mode 100644
index 000000000..fa92798cb
--- /dev/null
+++ b/docs/dev/engines/offline/search-indexer-engines.rst
@@ -0,0 +1,62 @@
+=================
+Local Search APIs
+=================
+
+.. sidebar:: further read
+
+   - `Comparison to alternatives
+     <https://docs.meilisearch.com/learn/what_is_meilisearch/comparison_to_alternatives.html>`_
+
+.. contents::
+   :depth: 1
+   :local:
+   :backlinks: entry
+
+.. sidebar:: info
+
+   Initial sponsored by `Search and Discovery Fund
+   <https://nlnet.nl/discovery>`_ of `NLnet Foundation <https://nlnet.nl/>`_.
+
+Administrators might find themselves wanting to integrate locally running search
+engines.  The following ones are supported for now:
+
+* `Elasticsearch`_
+* `Meilisearch`_
+* `Solr`_
+
+Each search engine is powerful, capable of full-text search.  All of the engines
+above are added to ``settings.yml`` just commented out, as you have to
+``base_url`` for all them.
+
+Please note that if you are not using HTTPS to access these engines, you have to
+enable HTTP requests by setting ``enable_http`` to ``True``.
+
+Furthermore, if you do not want to expose these engines on a public instance,
+you can still add them and limit the access by setting ``tokens`` as described
+in section :ref:`private engines`.
+
+.. _engine meilisearch:
+
+MeiliSearch
+===========
+
+.. automodule:: searx.engines.meilisearch
+  :members:
+
+
+.. _engine elasticsearch:
+
+Elasticsearch
+=============
+
+.. automodule:: searx.engines.elasticsearch
+  :members:
+
+.. _engine solr:
+
+Solr
+====
+
+.. automodule:: searx.engines.solr
+  :members:
+
diff --git a/docs/dev/engines/offline/sql-engines.rst b/docs/dev/engines/offline/sql-engines.rst
new file mode 100644
index 000000000..f0f5add0b
--- /dev/null
+++ b/docs/dev/engines/offline/sql-engines.rst
@@ -0,0 +1,121 @@
+.. _sql engines:
+
+===========
+SQL Engines
+===========
+
+.. sidebar:: further read
+
+   - `SQLite <https://www.sqlite.org/index.html>`_
+   - `PostgreSQL <https://www.postgresql.org>`_
+   - `MySQL <https://www.mysql.com>`_
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. sidebar:: info
+
+   Initial sponsored by `Search and Discovery Fund
+   <https://nlnet.nl/discovery>`_ of `NLnet Foundation <https://nlnet.nl/>`_.
+
+With the *SQL engines* you can bind SQL databases into SearXNG.  The following
+Relational Database Management System (RDBMS) are supported:
+
+- :ref:`engine sqlite`
+- :ref:`engine postgresql`
+- :ref:`engine mysql_server`
+
+All of the engines above are just commented out in the :origin:`settings.yml
+<searx/settings.yml>`, as you have to set the required attributes for the
+engines, e.g. ``database:`` ...
+
+.. code:: yaml
+
+   - name: ...
+     engine: {sqlite|postgresql|mysql_server}
+     database: ...
+     result_template: {template_name}
+     query_str: ...
+
+By default, the engines use the ``key-value`` template for displaying results /
+see :origin:`simple <searx/templates/simple/result_templates/key-value.html>`
+theme.  If you are not satisfied with the original result layout, you can use
+your own template, set ``result_template`` attribute to ``{template_name}`` and
+place the templates at::
+
+  searx/templates/{theme_name}/result_templates/{template_name}
+
+If you do not wish to expose these engines on a public instance, you can still
+add them and limit the access by setting ``tokens`` as described in section
+:ref:`private engines`.
+
+
+Extra Dependencies
+==================
+
+For using :ref:`engine postgresql` or :ref:`engine mysql_server` you need to
+install additional packages in Python's Virtual Environment of your SearXNG
+instance.  To switch into the environment (:ref:`searxng-src`) you can use
+:ref:`searxng.sh`::
+
+  $ sudo utils/searxng.sh instance cmd bash
+  (searxng-pyenv)$ pip install ...
+
+
+Configure the engines
+=====================
+
+The configuration of the new database engines are similar.  You must put a valid
+SQL-SELECT query in ``query_str``.  At the moment you can only bind at most one
+parameter in your query.  By setting the attribute ``limit`` you can define how
+many results you want from the SQL server.  Basically, it is the same as the
+``LIMIT`` keyword in SQL.
+
+Please, do not include ``LIMIT`` or ``OFFSET`` in your SQL query as the engines
+rely on these keywords during paging.  If you want to configure the number of
+returned results use the option ``limit``.
+
+.. _engine sqlite:
+
+SQLite
+------
+
+.. sidebar:: info
+
+   - :origin:`sqlite.py <searx/engines/sqlite.py>`
+
+.. automodule:: searx.engines.sqlite
+  :members:
+
+
+.. _engine postgresql:
+
+PostgreSQL
+----------
+
+.. _psycopg2: https://www.psycopg.org/install
+
+.. sidebar:: info
+
+   - :origin:`postgresql.py <searx/engines/postgresql.py>`
+   - ``pip install`` `psycopg2-binary <psycopg2>`_
+
+.. automodule:: searx.engines.postgresql
+  :members:
+
+.. _engine mysql_server:
+
+MySQL
+-----
+
+.. sidebar:: info
+
+   - :origin:`mysql_server.py <searx/engines/mysql_server.py>`
+   - ``pip install`` :pypi:`mysql-connector-python <mysql-connector-python>`
+
+
+.. automodule:: searx.engines.mysql_server
+  :members:
+
diff --git a/docs/dev/offline_engines.rst b/docs/dev/engines/offline_concept.rst
index bfb2664f5..ddb34fc60 100644
--- a/docs/dev/offline_engines.rst
+++ b/docs/dev/engines/offline_concept.rst
@@ -1,15 +1,14 @@
-.. _offline engines:
-
 ===============
-Offline Engines
+Offline Concept
 ===============
 
 .. sidebar:: offline engines
 
    - :ref:`demo offline engine`
-   - :ref:`sql engines`
    - :ref:`engine command`
-   - :origin:`Redis <searx/engines/redis_server.py>`
+   - :ref:`sql engines`
+   - :ref:`nosql engines`
+   - :py:obj:`searx.search.processors.offline`
 
 To extend the functionality of SearXNG, offline engines are going to be
 introduced.  An offline engine is an engine which does not need Internet
@@ -31,7 +30,6 @@ Programming Interface
   in advance.
 
 :py:func:`search(query, params) <searx.engines.demo_offline.searc>`
-
   Each offline engine has a function named ``search``.  This function is
   responsible to perform a search and return the results in a presentable
   format. (Where *presentable* means presentable by the selected result
@@ -69,10 +67,3 @@ administrators can set token(s) for each of the :ref:`private engines`.  If a
 query contains a valid token, then SearXNG performs the requested private
 search.  If not, requests from an offline engines return errors.
 
-
-Acknowledgement
-===============
-
-This development was sponsored by `Search and Discovery Fund
-<https://nlnet.nl/discovery>`_ of `NLnet Foundation <https://nlnet.nl/>`_ .
-
diff --git a/docs/dev/engines/online/annas_archive.rst b/docs/dev/engines/online/annas_archive.rst
new file mode 100644
index 000000000..db88e5069
--- /dev/null
+++ b/docs/dev/engines/online/annas_archive.rst
@@ -0,0 +1,13 @@
+.. _annas_archive engine:
+
+==============
+Anna's Archive
+==============
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. automodule:: searx.engines.annas_archive
+   :members:
diff --git a/docs/dev/engines/online/archlinux.rst b/docs/dev/engines/online/archlinux.rst
new file mode 100644
index 000000000..834fffa43
--- /dev/null
+++ b/docs/dev/engines/online/archlinux.rst
@@ -0,0 +1,14 @@
+.. _archlinux engine:
+
+==========
+Arch Linux
+==========
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. automodule:: searx.engines.archlinux
+  :members:
+
diff --git a/docs/dev/engines/online/bing.rst b/docs/dev/engines/online/bing.rst
new file mode 100644
index 000000000..19c31aa80
--- /dev/null
+++ b/docs/dev/engines/online/bing.rst
@@ -0,0 +1,43 @@
+.. _bing engines:
+
+============
+Bing Engines
+============
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+
+.. _bing web engine:
+
+Bing WEB
+========
+
+.. automodule:: searx.engines.bing
+  :members:
+
+.. _bing images engine:
+
+Bing Images
+===========
+
+.. automodule:: searx.engines.bing_images
+  :members:
+
+.. _bing videos engine:
+
+Bing Videos
+===========
+
+.. automodule:: searx.engines.bing_videos
+  :members:
+
+.. _bing news engine:
+
+Bing News
+=========
+
+.. automodule:: searx.engines.bing_news
+  :members:
diff --git a/docs/dev/engines/online/dailymotion.rst b/docs/dev/engines/online/dailymotion.rst
new file mode 100644
index 000000000..c661172e5
--- /dev/null
+++ b/docs/dev/engines/online/dailymotion.rst
@@ -0,0 +1,13 @@
+.. _dailymotion engine:
+
+===========
+Dailymotion
+===========
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. automodule:: searx.engines.dailymotion
+  :members:
diff --git a/docs/dev/engines/online/duckduckgo.rst b/docs/dev/engines/online/duckduckgo.rst
new file mode 100644
index 000000000..d0d18eb8a
--- /dev/null
+++ b/docs/dev/engines/online/duckduckgo.rst
@@ -0,0 +1,22 @@
+.. _duckduckgo engines:
+
+=================
+DukcDukGo Engines
+=================
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. automodule:: searx.engines.duckduckgo
+   :members:
+
+.. automodule:: searx.engines.duckduckgo_images
+   :members:
+
+.. automodule:: searx.engines.duckduckgo_definitions
+   :members:
+
+.. automodule:: searx.engines.duckduckgo_weather
+   :members:
diff --git a/docs/dev/engines/online/google.rst b/docs/dev/engines/online/google.rst
new file mode 100644
index 000000000..9085070bd
--- /dev/null
+++ b/docs/dev/engines/online/google.rst
@@ -0,0 +1,76 @@
+.. _google engines:
+
+==============
+Google Engines
+==============
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+
+.. _google API:
+
+Google API
+==========
+
+.. _Query Parameter Definitions:
+   https://developers.google.com/custom-search/docs/xml_results#WebSearch_Query_Parameter_Definitions
+
+SearXNG's implementation of the Google API is mainly done in
+:py:obj:`get_google_info <searx.engines.google.get_google_info>`.
+
+For detailed description of the *REST-full* API see: `Query Parameter
+Definitions`_.  The linked API documentation can sometimes be helpful during
+reverse engineering.  However, we cannot use it in the freely accessible WEB
+services; not all parameters can be applied and some engines are more *special*
+than other (e.g. :ref:`google news engine`).
+
+
+.. _google web engine:
+
+Google WEB
+==========
+
+.. automodule:: searx.engines.google
+  :members:
+
+.. _google autocomplete:
+
+Google Autocomplete
+====================
+
+.. autofunction:: searx.autocomplete.google_complete
+
+.. _google images engine:
+
+Google Images
+=============
+
+.. automodule:: searx.engines.google_images
+  :members:
+
+.. _google videos engine:
+
+Google Videos
+=============
+
+.. automodule:: searx.engines.google_videos
+  :members:
+
+.. _google news engine:
+
+Google News
+===========
+
+.. automodule:: searx.engines.google_news
+  :members:
+
+.. _google scholar engine:
+
+Google Scholar
+==============
+
+.. automodule:: searx.engines.google_scholar
+  :members:
diff --git a/docs/dev/engines/online/peertube.rst b/docs/dev/engines/online/peertube.rst
new file mode 100644
index 000000000..bedf055fb
--- /dev/null
+++ b/docs/dev/engines/online/peertube.rst
@@ -0,0 +1,27 @@
+.. _peertube engines:
+
+================
+Peertube Engines
+================
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+
+.. _peertube video engine:
+
+Peertube Video
+==============
+
+.. automodule:: searx.engines.peertube
+  :members:
+
+.. _sepiasearch engine:
+
+SepiaSearch
+===========
+
+.. automodule:: searx.engines.sepiasearch
+  :members:
diff --git a/docs/dev/engines/online/recoll.rst b/docs/dev/engines/online/recoll.rst
new file mode 100644
index 000000000..2f1a1e4df
--- /dev/null
+++ b/docs/dev/engines/online/recoll.rst
@@ -0,0 +1,13 @@
+.. _engine recoll:
+
+=============
+Recoll Engine
+=============
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. automodule:: searx.engines.recoll
+   :members:
diff --git a/docs/dev/engines/online/startpage.rst b/docs/dev/engines/online/startpage.rst
new file mode 100644
index 000000000..89e3ad10b
--- /dev/null
+++ b/docs/dev/engines/online/startpage.rst
@@ -0,0 +1,13 @@
+.. _startpage engines:
+
+=================
+Startpage Engines
+=================
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. automodule:: searx.engines.startpage
+   :members:
diff --git a/docs/dev/engines/online/torznab.rst b/docs/dev/engines/online/torznab.rst
new file mode 100644
index 000000000..9056b60d0
--- /dev/null
+++ b/docs/dev/engines/online/torznab.rst
@@ -0,0 +1,13 @@
+.. _torznab engine:
+
+==============
+Torznab WebAPI
+==============
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. automodule:: searx.engines.torznab
+   :members:
diff --git a/docs/dev/engines/online/wikipedia.rst b/docs/dev/engines/online/wikipedia.rst
new file mode 100644
index 000000000..d4920f0f6
--- /dev/null
+++ b/docs/dev/engines/online/wikipedia.rst
@@ -0,0 +1,27 @@
+.. _wikimedia engines:
+
+=========
+Wikimedia
+=========
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+
+.. _wikipedia engine:
+
+Wikipedia
+=========
+
+.. automodule:: searx.engines.wikipedia
+  :members:
+
+.. _wikidata engine:
+
+Wikidata
+=========
+
+.. automodule:: searx.engines.wikidata
+  :members:
diff --git a/docs/dev/engines/online/yahoo.rst b/docs/dev/engines/online/yahoo.rst
new file mode 100644
index 000000000..96c1e2774
--- /dev/null
+++ b/docs/dev/engines/online/yahoo.rst
@@ -0,0 +1,13 @@
+.. _yahoo engine:
+
+============
+Yahoo Engine
+============
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. automodule:: searx.engines.yahoo
+  :members:
diff --git a/docs/dev/engines/online_url_search/tineye.rst b/docs/dev/engines/online_url_search/tineye.rst
new file mode 100644
index 000000000..3f4db7e0e
--- /dev/null
+++ b/docs/dev/engines/online_url_search/tineye.rst
@@ -0,0 +1,14 @@
+.. _tineye engine:
+
+======
+Tineye
+======
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. automodule:: searx.engines.tineye
+  :members:
+
diff --git a/docs/dev/engines/xpath.rst b/docs/dev/engines/xpath.rst
new file mode 100644
index 000000000..42c4d47b6
--- /dev/null
+++ b/docs/dev/engines/xpath.rst
@@ -0,0 +1,14 @@
+.. _xpath engine:
+
+============
+XPath Engine
+============
+
+.. contents::
+   :depth: 2
+   :local:
+   :backlinks: entry
+
+.. automodule:: searx.engines.xpath
+  :members:
+
diff --git a/docs/dev/index.rst b/docs/dev/index.rst
index 39be0885c..aa0667c58 100644
--- a/docs/dev/index.rst
+++ b/docs/dev/index.rst
@@ -4,12 +4,10 @@ Developer documentation
 
 .. toctree::
    :maxdepth: 2
-   :caption: Contents
 
    quickstart
    contribution_guide
-   engine_overview
-   offline_engines
+   engines/index
    search_api
    plugins
    translation
diff --git a/docs/dev/lxcdev.rst b/docs/dev/lxcdev.rst
index ef603e9fd..854b193ff 100644
--- a/docs/dev/lxcdev.rst
+++ b/docs/dev/lxcdev.rst
@@ -22,7 +22,7 @@ In this article we will show, how you can make use of Linux Containers (LXC_) in
    section :ref:`internet connectivity docker`.
 
 
-.. contents:: Contents
+.. contents::
    :depth: 2
    :local:
    :backlinks: entry
diff --git a/docs/dev/makefile.rst b/docs/dev/makefile.rst
index bdf7f0f49..ad5665de7 100644
--- a/docs/dev/makefile.rst
+++ b/docs/dev/makefile.rst
@@ -22,7 +22,7 @@ Calling the ``help`` target gives a first overview (``make help``):
 
 .. program-output:: bash -c "cd ..; make --no-print-directory help"
 
-.. contents:: Contents
+.. contents::
    :depth: 2
    :local:
    :backlinks: entry
@@ -243,14 +243,14 @@ calling ``make clean`` stop all processes using the :ref:`make install` or
 We describe the usage of the ``doc.*`` targets in the :ref:`How to contribute /
 Documentation <contrib docs>` section.  If you want to edit the documentation
 read our :ref:`make docs.live` section.  If you are working in your own brand,
-adjust your :ref:`settings global`.
+adjust your :ref:`settings brand`.
 
 .. _make docs.gh-pages:
 
 ``make docs.gh-pages``
 ======================
 
-To deploy on github.io first adjust your :ref:`settings global`.  For any
+To deploy on github.io first adjust your :ref:`settings brand`.  For any
 further read :ref:`deploy on github.io`.
 
 .. _make test:
diff --git a/docs/dev/reST.rst b/docs/dev/reST.rst
index b19a7096e..47af0b130 100644
--- a/docs/dev/reST.rst
+++ b/docs/dev/reST.rst
@@ -37,7 +37,7 @@ docs.live <make docs.live>` to build HTML while editing.
    - DOT_, `Graphviz's dot`_, Graphviz_
 
 
-.. contents:: Contents
+.. contents::
    :depth: 3
    :local:
    :backlinks: entry
diff --git a/docs/dev/searxng_extra/index.rst b/docs/dev/searxng_extra/index.rst
index c2b5c312b..7bca3c0d4 100644
--- a/docs/dev/searxng_extra/index.rst
+++ b/docs/dev/searxng_extra/index.rst
@@ -9,7 +9,6 @@ developers.
 
 .. toctree::
    :maxdepth: 2
-   :caption: Contents
 
    update
    standalone_searx.py