[mod] replace /help by /info pages and include pages in project docs

This patch implements a bolierplate to share content from info-pages of the
SearXNG instance (URL /info) with the project documentation (path /docs/user).

The info pages are using Markdown (CommonMark), to include them in the project
documentation (reST) the myst-parser [1] is used in the Sphinx-doc build chain.

If base_url is known (defined in settings.yml) links to the instance are also
inserted into the project documentation::

    searxng_extra/docs_prebuild

[1] https://www.sphinx-doc.org/en/master/usage/markdown.html

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

21 files changed, 423 insertions, 168 deletions

diff --git a/docs/conf.py b/docs/conf.py
index 2f58bdb12..89d6bb8f6 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -35,7 +35,7 @@ master_doc = "index"
 source_suffix = '.rst'
 numfig = True
 
-exclude_patterns = ['build-templates/*.rst']
+exclude_patterns = ['build-templates/*.rst', 'user/*.md']
 
 import searx.engines
 import searx.plugins
@@ -94,7 +94,6 @@ extlinks['pull-searx'] = ('https://github.com/searx/searx/pull/%s', 'PR ')
 # links to custom brand
 extlinks['origin'] = (GIT_URL + '/blob/' + GIT_BRANCH + '/%s', 'git://')
 extlinks['patch'] = (GIT_URL + '/commit/%s', '#')
-extlinks['search'] = (SEARXNG_URL + '/%s', '#')
 extlinks['docs'] = (DOCS_URL + '/%s', 'docs: ')
 extlinks['pypi'] = ('https://pypi.org/project/%s', 'PyPi: ')
 extlinks['man'] = ('https://manpages.debian.org/jump?q=%s', '')
@@ -123,8 +122,11 @@ extensions = [
     'linuxdoc.rstFlatTable',    # Implementation of the 'flat-table' reST-directive.
     'linuxdoc.kfigure',         # Sphinx extension which implements scalable image handling.
     "sphinx_tabs.tabs", # https://github.com/djungelorm/sphinx-tabs
+    'myst_parser',  # https://www.sphinx-doc.org/en/master/usage/markdown.html
 ]
 
+suppress_warnings = ['myst.domains']
+
 intersphinx_mapping = {
     "python": ("https://docs.python.org/3/", None),
     "flask": ("https://flask.palletsprojects.com/", None),
diff --git a/docs/src/searx.infopage.rst b/docs/src/searx.infopage.rst
new file mode 100644
index 000000000..243e5b0bd
--- /dev/null
+++ b/docs/src/searx.infopage.rst
@@ -0,0 +1,8 @@
+.. _searx.infopage:
+
+================
+Online ``/info``
+================
+
+.. automodule:: searx.infopage
+  :members:
diff --git a/docs/user/.gitignore b/docs/user/.gitignore
new file mode 100644
index 000000000..2e1fa2d52
--- /dev/null
+++ b/docs/user/.gitignore
@@ -0,0 +1 @@
+*.md
\ No newline at end of file
diff --git a/docs/user/index.rst b/docs/user/index.rst
index 0cdb7310c..dc9fb0da2 100644
--- a/docs/user/index.rst
+++ b/docs/user/index.rst
@@ -2,8 +2,14 @@
 User documentation
 ==================
 
-.. toctree::
-   :maxdepth: 2
-   :caption: Contents
+.. contents:: Contents
+   :depth: 3
+   :local:
+   :backlinks: entry
+
+
+.. _search-syntax:
+
+.. include:: search-syntax.md
+   :parser: myst_parser.sphinx_
 
-   search_syntax
diff --git a/docs/user/search_syntax.rst b/docs/user/search_syntax.rst
deleted file mode 100644
index 346b3162d..000000000
--- a/docs/user/search_syntax.rst
+++ /dev/null
@@ -1,39 +0,0 @@
-
-.. _search-syntax:
-
-=============
-Search syntax
-=============
-
-SearXNG allows you to modify the default categories, engines and search language
-via the search query.
-
-Prefix ``!``
-  to set Category/engine
-
-Prefix: ``:``
-  to set language
-
-Abbrevations of the engines and languages are also accepted.  Engine/category
-modifiers are chainable and inclusive (e.g. with :search:`!it !ddg !wp qwer
-<?q=%21it%20%21ddg%20%21wp%20qwer>` search in IT category **and** duckduckgo
-**and** wikipedia for ``qwer``).
-
-See the :search:`/preferences page <preferences>` for the list of engines,
-categories and languages.
-
-Examples
-========
-
-Search in wikipedia for ``qwer``:
-
-- :search:`!wp qwer <?q=%21wp%20qwer>` or
-- :search:`!wikipedia qwer :search:<?q=%21wikipedia%20qwer>`
-
-Image search:
-
-- :search:`!images Cthulhu <?q=%21images%20Cthulhu>`
-
-Custom language in wikipedia:
-
-- :search:`:hu !wp hackerspace <?q=%3Ahu%20%21wp%20hackerspace>`
diff --git a/manage b/manage
index 678f64017..e70b7f4dd 100755
--- a/manage
+++ b/manage
@@ -419,6 +419,7 @@ docs.prebuild() {
         ./utils/searx.sh doc   | cat > "${DOCS_BUILD}/includes/searx.rst"
         ./utils/filtron.sh doc | cat > "${DOCS_BUILD}/includes/filtron.rst"
         ./utils/morty.sh doc   | cat > "${DOCS_BUILD}/includes/morty.rst"
+        pyenv.cmd searxng_extra/docs_prebuild
     )
     dump_return $?
 }
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 7460caf78..6b4efa2f8 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -14,6 +14,7 @@ sphinx-jinja==1.4.0
 sphinx-tabs==3.2.0
 sphinxcontrib-programoutput==0.17
 sphinx-autobuild==2021.3.14
+myst-parser==0.17.0
 linuxdoc==20211220
 aiounittest==1.4.1
 yamllint==1.26.3
diff --git a/searx/help/en/about.md b/searx/info/en/about.md
index dd7cd4515..9f323870e 100644
--- a/searx/help/en/about.md
+++ b/searx/info/en/about.md
@@ -1,30 +1,29 @@
 # About SearXNG
 
 SearXNG is a fork from the well-known [searx] [metasearch engine], aggregating
-the results of other [search engines][url_for:preferences] while not storing
-information about its users.
+the results of other {{link('search engines', 'preferences')}} while not
+storing information about its users.
 
 More about SearXNG ...
 
-* [SearXNG sources][brand.git_url]
+* [SearXNG sources]({{GIT_URL}})
 * [weblate]
 
----
 
 ## Why use it?
 
-* SearXNG may not offer you as personalised results as Google,
-  but it doesn't generate a profile about you.
+* SearXNG may not offer you as personalised results as Google, but it doesn't
+  generate a profile about you.
 
-* SearXNG doesn't care about what you search for, never shares anything
-  with a third party, and it can't be used to compromise you.
+* SearXNG doesn't care about what you search for, never shares anything with a
+  third party, and it can't be used to compromise you.
 
-* SearXNG is free software, the code is 100% open and you can help
-  to make it better.  See more on [SearXNG sources][brand.git_url].
+* SearXNG is free software, the code is 100% open and you can help to make it
+  better.  See more on [SearXNG sources]({{GIT_URL}}).
 
-If you do care about privacy, want to be a conscious user, or otherwise
-believe in digital freedom, make SearXNG your default search engine or run
-it on your own server
+If you do care about privacy, want to be a conscious user, or otherwise believe
+in digital freedom, make SearXNG your default search engine or run it on your
+own server
 
 ## Technical details - How does it work?
 
@@ -37,35 +36,40 @@ exception: searx uses the search bar to perform GET requests.  SearXNG can be
 added to your browser's search bar; moreover, it can be set as the default
 search engine.
 
-<span id='add to browser'></span>
 ## How to set as the default search engine?
 
 SearXNG supports [OpenSearch].  For more information on changing your default
 search engine, see your browser's documentation:
 
-* [Firefox](https://support.mozilla.org/en-US/kb/add-or-remove-search-engine-firefox)
-* [Microsoft Edge](https://support.microsoft.com/en-us/help/4028574/microsoft-edge-change-the-default-search-engine)
-* Chromium-based browsers [only add websites that the user navigates to without a path.](https://www.chromium.org/tab-to-search)
+* [Firefox]
+* [Microsoft Edge]
+* Chromium-based browsers [only add websites that the user navigates to without
+  a path.](https://www.chromium.org/tab-to-search)
 
 ## Where to find anonymous usage statistics of this instance ?
 
-[Stats page][url_for:stats] contains some useful data about the engines used.
+{{link('Stats page', 'stats')}} contains some useful data about the engines
+used.
 
 ## How can I make it my own?
 
-SearXNG appreciates your concern regarding logs, so take the code from
-the [SearXNG project][brand.git_url] and run it yourself!
+SearXNG appreciates your concern regarding logs, so take the code from the
+[SearXNG project]({{GIT_URL}}) and run it yourself!
 
-Add your instance to this [list of public instances][brand.public_instances] to
-help other people reclaim their privacy and make the Internet freer!  The more
-decentralized the Internet is, the more freedom we have!
+Add your instance to this [list of public
+instances]({{get_setting('brand.public_instances')}}) to help other people
+reclaim their privacy and make the Internet freer!  The more decentralized the
+Internet is, the more freedom we have!
 
 ## Where are the docs & code of this instance?
 
-See the [SearXNG docs][brand.docs_url] and [SearXNG sources][brand.git_url]
+See the [SearXNG docs]({{get_setting('brand.docs_url')}}) and [SearXNG
+sources]({{GIT_URL}})
 
 [searx]: https://github.com/searx/searx
 [metasearch engine]: https://en.wikipedia.org/wiki/Metasearch_engine
 [weblate]: https://weblate.bubu1.eu/projects/searxng/
 [seeks project]: https://beniz.github.io/seeks/
 [OpenSearch]: https://github.com/dewitt/opensearch/blob/master/opensearch-1-1-draft-6.md
+[Firefox]: https://support.mozilla.org/en-US/kb/add-or-remove-search-engine-firefox
+[Microsoft Edge]: https://support.microsoft.com/en-us/help/4028574/microsoft-edge-change-the-default-search-engine
diff --git a/searx/info/en/search-syntax.md b/searx/info/en/search-syntax.md
new file mode 100644
index 000000000..ae820dfbc
--- /dev/null
+++ b/searx/info/en/search-syntax.md
@@ -0,0 +1,35 @@
+# Search syntax
+
+SearXNG allows you to modify the default categories, engines and search language
+via the search query.
+
+Prefix `!` to set category and engine names.
+
+Prefix: `:` to set the language.
+
+Abbrevations of the engines and languages are also accepted.  Engine/category
+modifiers are chainable and inclusive.  E.g. with {{search('!map !ddg !wp paris')}}
+search in map category **and** duckduckgo **and** wikipedia for
+`paris`.
+
+See the {{link('preferences', 'preferences')}} for the list of engines,
+categories and languages.
+
+## Examples
+
+Search in wikipedia for `paris`:
+
+* {{search('!wp paris')}}
+* {{search('!wikipedia paris')}}
+
+Search in category `map` for `paris`:
+
+* {{search('!map paris')}}
+
+Image search:
+
+* {{search('!images Wau Holland')}}
+
+Custom language in wikipedia:
+
+* {{search(':fr !wp Wau Holland')}}
diff --git a/searx/infopage/__init__.py b/searx/infopage/__init__.py
new file mode 100644
index 000000000..d7736a934
--- /dev/null
+++ b/searx/infopage/__init__.py
@@ -0,0 +1,191 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+# lint: pylint
+# pyright: basic
+"""Render SearXNG instance documentation.
+
+Usage in a Flask app route:
+
+.. code:: python
+
+  from searx import infopage
+
+  _INFO_PAGES = infopage.InfoPageSet(infopage.MistletoePage)
+
+  @app.route('/info/<pagename>', methods=['GET'])
+  def info(pagename):
+
+      locale = request.preferences.get_value('locale')
+      page = _INFO_PAGES.get_page(pagename, locale)
+
+"""
+
+__all__ = ['InfoPage', 'MistletoePage', 'InfoPageSet']
+
+import os.path
+import logging
+from functools import cached_property
+import typing
+
+import urllib.parse
+import jinja2
+from flask.helpers import url_for
+import mistletoe
+
+from .. import get_setting
+from ..version import GIT_URL
+
+logger = logging.getLogger('doc')
+
+
+class InfoPage:
+    """A page of the :py:obj:`online documentation <InfoPageSet>`."""
+
+    def __init__(self, fname, base_url=None):
+        self.fname = fname
+        self.base_url = base_url
+
+    @cached_property
+    def raw_content(self):
+        """Raw content of the page (without any jinja rendering)"""
+        with open(self.fname, 'r', encoding='utf-8') as f:
+            return f.read()
+
+    @cached_property
+    def content(self):
+        """Content of the page (rendered in a Jinja conntext)"""
+        ctx = self.get_ctx()
+        template = jinja2.Environment().from_string(self.raw_content)
+        return template.render(**ctx)
+
+    @cached_property
+    def title(self):
+        """Title of the content (without any markup)"""
+        t = ""
+        for l in self.raw_content.split('\n'):
+            if l.startswith('# '):
+                t = l.strip('# ')
+        return t
+
+    def get_ctx(self):  # pylint: disable=no-self-use
+        """Jinja context to render :py:obj:`InfoPage.content`"""
+
+        def _md_link(name, url):
+            url = url_for(url)
+            if self.base_url:
+                url = self.base_url + url
+            return "[%s](%s)" % (name, url)
+
+        def _md_search(query):
+            url = '%s?q=%s' % (url_for('search'), urllib.parse.quote(query))
+            if self.base_url:
+                url = self.base_url + url
+            return '[%s](%s)' % (query, url)
+
+        ctx = {}
+        ctx['GIT_URL'] = GIT_URL
+        ctx['get_setting'] = get_setting
+        ctx['link'] = _md_link
+        ctx['search'] = _md_search
+
+        return ctx
+
+    def render(self):
+        """Render / return content"""
+        return self.content
+
+
+class MistletoePage(InfoPage):
+    """A HTML page of the :py:obj:`online documentation <InfoPageSet>`."""
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+    @cached_property
+    def html(self):
+        """HTML representation of this page"""
+        return self.render()
+
+    def render(self):
+        """Render Markdown (CommonMark_) to HTML by using mistletoe_.
+
+        .. _CommonMark: https://commonmark.org/
+        .. _mistletoe: https://github.com/miyuchina/mistletoe
+
+        """
+        return mistletoe.markdown(self.content)
+
+
+_INFO_FOLDER = os.path.abspath(os.path.join(os.path.dirname(__file__), '..', 'info'))
+
+
+class InfoPageSet:  # pylint: disable=too-few-public-methods
+    """Cached rendering of the online documentation a SearXNG instance has.
+
+    :param page_class: render online documentation by :py:obj:`InfoPage` parser.
+    :type page_class: :py:obj:`InfoPage`
+    """
+
+    def __init__(self, page_class: typing.Type[InfoPage], base_url=None):
+        self.page_class = page_class
+        self.base_url = base_url
+        self.CACHE: typing.Dict[tuple, InfoPage] = {}
+
+        # future: could be set from settings.xml
+
+        self.folder: str = _INFO_FOLDER
+        """location of the Markdwon files"""
+
+        self.i18n_origin: str = 'en'
+        """default language"""
+
+        self.l10n: typing.List = [
+            'en',
+        ]
+        """list of supported languages (aka locales)"""
+
+        self.toc: typing.List = [
+            'search-syntax',
+            'about',
+        ]
+        """list of articles in the online documentation"""
+
+    def get_page(self, pagename: str, locale: typing.Optional[str] = None):
+        """Return ``pagename`` instance of :py:obj:`InfoPage`
+
+        :param pagename: name of the page, a value from :py:obj:`InfoPageSet.toc`
+        :type pagename: str
+
+        :param locale: language of the page, e.g. ``en``, ``zh_Hans_CN``
+                       (default: :py:obj:`InfoPageSet.i18n_origin`)
+        :type locale: str
+
+        """
+        if pagename not in self.toc:
+            return None
+        if locale is not None and locale not in self.l10n:
+            return None
+
+        locale = locale or self.i18n_origin
+        cache_key = (pagename, locale)
+        page = self.CACHE.get(cache_key)
+
+        if page is not None:
+            return page
+
+        # not yet instantiated
+
+        fname = os.path.join(self.folder, locale, pagename) + '.md'
+        if not os.path.exists(fname):
+            logger.error('file %s does not exists', fname)
+            return None
+
+        page = self.page_class(fname, self.base_url)
+        self.CACHE[cache_key] = page
+        return page
+
+    def all_pages(self, locale: typing.Optional[str] = None):
+        """Iterate over all pages"""
+        locale = locale or self.i18n_origin
+        for pagename in self.toc:
+            page = self.get_page(pagename, locale)
+            yield pagename, page
diff --git a/searx/templates/oscar/help.html b/searx/templates/oscar/help.html
deleted file mode 100644
index bf311fb4a..000000000
--- a/searx/templates/oscar/help.html
+++ /dev/null
@@ -1,12 +0,0 @@
-{% extends "oscar/base.html" %}
-{% block title %}{{ page.title }} - {% endblock %}
-{% block content %}
-<ul class="nav nav-tabs">
-{% for name, page in all_pages %}
-  <li {% if name == page_filename %}class="active"{% endif %}>
-    <a href="{{name}}">{{page.title}}</a>
-  </li>
-{% endfor %}
-</ul>
-{{ page.content | safe }}
-{% endblock %}
diff --git a/searx/templates/oscar/info.html b/searx/templates/oscar/info.html
new file mode 100644
index 000000000..3a696da50
--- /dev/null
+++ b/searx/templates/oscar/info.html
@@ -0,0 +1,12 @@
+{% extends "oscar/base.html" %}
+{% block title %}{{ active_page.title }} - {% endblock %}
+{% block content %}
+<ul class="nav nav-tabs">
+{% for pagename, page in all_pages('en') %}
+  <li {% if pagename == active_pagename %}class="active"{% endif %}>
+    <a href="{{pagename}}">{{page.title}}</a>
+  </li>
+{% endfor %}
+</ul>
+{{ active_page.html | safe }}
+{% endblock %}
diff --git a/searx/templates/oscar/navbar.html b/searx/templates/oscar/navbar.html
index b1d344c11..4c0ec0068 100644
--- a/searx/templates/oscar/navbar.html
+++ b/searx/templates/oscar/navbar.html
@@ -3,7 +3,7 @@
         <a href="{{ url_for('index') }}">{{ instance_name }}</a>{{- "" -}}
     </span>{{- "" -}}
     <span class="{% if rtl %}pull-left{% else %}pull-right{% endif %}">{{- "" -}}
-        <a href="{{ url_for('help_page', pagename='about') }}">{{ _('about') }}</a>{{- "" -}}
+        <a href="{{ url_for('info', pagename='about', locale=current_locale) }}">{{ _('about') }}</a>{{- "" -}}
         <a href="{{ url_for('preferences') }}">{{ _('preferences') }}</a>{{- "" -}}
     </span>{{- "" -}}
 </div>
diff --git a/searx/templates/simple/base.html b/searx/templates/simple/base.html
index 644c6df9a..135a95669 100644
--- a/searx/templates/simple/base.html
+++ b/searx/templates/simple/base.html
@@ -58,7 +58,7 @@
   </main>
   <footer>
     <p>
-    {{ _('Powered by') }} <a href="{{ url_for('help_page', pagename='about') }}">searxng</a> - {{ searx_version }} — {{ _('a privacy-respecting, hackable metasearch engine') }}<br/>
+    {{ _('Powered by') }} <a href="{{ url_for('info', pagename='about', locale=current_locale) }}">searxng</a> - {{ searx_version }} — {{ _('a privacy-respecting, hackable metasearch engine') }}<br/>
         <a href="{{ searx_git_url }}">{{ _('Source code') }}</a> |
         <a href="{{ get_setting('brand.issue_url') }}">{{ _('Issue tracker') }}</a> |
         <a href="{{ url_for('stats') }}">{{ _('Engine stats') }}</a> |
diff --git a/searx/templates/simple/help.html b/searx/templates/simple/help.html
deleted file mode 100644
index 5f571ae01..000000000
--- a/searx/templates/simple/help.html
+++ /dev/null
@@ -1,12 +0,0 @@
-{% extends 'simple/page_with_header.html' %}
-{% block title %}{{ page.title }} - {% endblock %}
-{% block content %}
-<ul class="tabs">
-{% for name, page in all_pages %}
-  <li>
-    <a href="{{name}}" {% if name == page_filename %}class="active"{% endif %}>{{page.title}}</a>
-  </li>
-{% endfor %}
-</ul>
-{{ page.content | safe }}
-{% endblock %}
diff --git a/searx/templates/simple/info.html b/searx/templates/simple/info.html
new file mode 100644
index 000000000..ef6b343ad
--- /dev/null
+++ b/searx/templates/simple/info.html
@@ -0,0 +1,14 @@
+{% extends 'simple/page_with_header.html' %}
+{% block title %}{{ active_page.title }} - {% endblock %}
+{% block content %}
+<ul class="tabs">
+{% for pagename, page in all_pages('en') %}
+  <li>
+    <a href="{{pagename}}" {% if pagename == active_pagename %}class="active"{% endif %}>{{page.title}}</a>
+  </li>
+{% endfor %}
+</ul>
+<div class="info-page {{pagename}}">
+  {{- active_page.html | safe -}}
+</div>
+{% endblock %}
diff --git a/searx/user_help.py b/searx/user_help.py
deleted file mode 100644
index 1914c7c84..000000000
--- a/searx/user_help.py
+++ /dev/null
@@ -1,61 +0,0 @@
-# pyright: basic
-from typing import Dict, NamedTuple
-import pkg_resources
-
-import flask
-from flask.helpers import url_for
-import mistletoe
-
-from . import get_setting
-from .version import GIT_URL
-
-
-class HelpPage(NamedTuple):
-    title: str
-    content: str
-
-
-# Whenever a new .md file is added to help/ it needs to be added here
-_TOC = ('about',)
-
-PAGES: Dict[str, HelpPage] = {}
-""" Maps a filename under help/ without the file extension to the rendered page. """
-
-
-def render(app: flask.Flask):
-    """
-    Renders the user documentation. Must be called after all Flask routes have been
-    registered, because the documentation might try to link to them with Flask's `url_for`.
-
-    We render the user documentation once on startup to improve performance.
-    """
-
-    link_targets = {
-        'brand.git_url': GIT_URL,
-        'brand.public_instances': get_setting('brand.public_instances'),
-        'brand.docs_url': get_setting('brand.docs_url'),
-    }
-
-    base_url = get_setting('server.base_url') or None
-    # we specify base_url so that url_for works for base_urls that have a non-root path
-
-    with app.test_request_context(base_url=base_url):
-        link_targets['url_for:index'] = url_for('index')
-        link_targets['url_for:preferences'] = url_for('preferences')
-        link_targets['url_for:stats'] = url_for('stats')
-
-    define_link_targets = ''.join(f'[{name}]: {url}\n' for name, url in link_targets.items())
-
-    for pagename in _TOC:
-        file_content = pkg_resources.resource_string(__name__, 'help/en/' + pagename + '.md').decode()
-        markdown = define_link_targets + file_content
-        assert file_content.startswith('# ')
-        title = file_content.split('\n', maxsplit=1)[0].strip('# ')
-        content: str = mistletoe.markdown(markdown)
-
-        if pagename == 'about':
-            try:
-                content += pkg_resources.resource_string(__name__, 'templates/__common__/aboutextend.html').decode()
-            except FileNotFoundError:
-                pass
-        PAGES[pagename] = HelpPage(title=title, content=content)
diff --git a/searx/webapp.py b/searx/webapp.py
index 999b4f64b..5263aaf1b 100755
--- a/searx/webapp.py
+++ b/searx/webapp.py
@@ -56,8 +56,9 @@ from searx import (
     get_setting,
     settings,
     searx_debug,
-    user_help,
 )
+
+from searx import infopage
 from searx.data import ENGINE_DESCRIPTIONS
 from searx.results import Timing, UnresponsiveEngine
 from searx.settings_defaults import OUTPUT_FORMATS
@@ -660,6 +661,7 @@ def index():
         # fmt: off
         'index.html',
         selected_categories=get_selected_categories(request.preferences, request.form),
+        current_locale = request.preferences.get_value("locale"),
         # fmt: on
     )
 
@@ -864,6 +866,7 @@ def search():
         unresponsive_engines = __get_translated_errors(
             result_container.unresponsive_engines
         ),
+        current_locale = request.preferences.get_value("locale"),
         current_language = match_language(
             search_query.lang,
             settings['search']['languages'],
@@ -898,19 +901,29 @@ def __get_translated_errors(unresponsive_engines: Iterable[UnresponsiveEngine]):
 @app.route('/about', methods=['GET'])
 def about():
     """Redirect to about page"""
-    return redirect(url_for('help_page', pagename='about'))
+    locale = request.preferences.get_value('locale')
+    return redirect(url_for('info', pagename='about', locale=locale))
 
 
-@app.route('/help/en/<pagename>', methods=['GET'])
-def help_page(pagename):
-    """Render help page"""
-    page = user_help.PAGES.get(pagename)
+_INFO_PAGES = infopage.InfoPageSet(infopage.MistletoePage)
 
+
+@app.route('/info/<locale>/<pagename>', methods=['GET'])
+def info(pagename, locale):
+    """Render page of online user documentation"""
+
+    locale = locale or request.preferences.get_value('locale')
+    page = _INFO_PAGES.get_page(pagename, locale)
+    if page is None:
+        page = _INFO_PAGES.get_page(pagename)
     if page is None:
         flask.abort(404)
 
     return render(
-        'help.html', page=user_help.PAGES[pagename], all_pages=user_help.PAGES.items(), page_filename=pagename
+        'info.html',
+        all_pages=_INFO_PAGES.all_pages,
+        active_page=page,
+        active_pagename=pagename,
     )
 
 
@@ -1411,7 +1424,6 @@ werkzeug_reloader = flask_run_development or (searx_debug and __name__ == "__mai
 if not werkzeug_reloader or (werkzeug_reloader and os.environ.get("WERKZEUG_RUN_MAIN") == "true"):
     plugin_initialize(app)
     search_initialize(enable_checker=True, check_network=True, enable_metrics=settings['general']['enable_metrics'])
-    user_help.render(app)
 
 
 def run():
diff --git a/searxng_extra/docs_prebuild b/searxng_extra/docs_prebuild
new file mode 100755
index 000000000..73c9c99b1
--- /dev/null
+++ b/searxng_extra/docs_prebuild
@@ -0,0 +1,87 @@
+#!/usr/bin/env python
+# lint: pylint
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+"""Script that implements some prebuild tasks needed by target docs.prebuild
+"""
+
+import sys
+import os.path
+import time
+from searx import settings, get_setting
+from searx.infopage import InfoPageSet, InfoPage
+
+_doc_user = os.path.abspath(os.path.join(os.path.dirname(__file__), '..', 'docs', 'user'))
+
+def main():
+
+    DOC = None
+    base_url = get_setting('server.base_url', None)
+
+    if base_url:
+        DOC = _render_all_with_flask_ctx(base_url)
+    else:
+        DOC = _render_all()
+    for pagename, page in DOC.all_pages('en'):
+        fname = os.path.join(_doc_user, os.path.basename(page.fname))
+        with open(fname, 'w') as f:
+            f.write(page.content)
+
+
+class OfflinePage(InfoPage):
+
+    def get_ctx(self):  # pylint: disable=no-self-use
+        """Jinja context to render :py:obj:`DocPage.content` for offline purpose (no
+        links to SearXNG instance)"""
+
+        ctx = super().get_ctx()
+        ctx['link'] = lambda name, url: '`%s`' % name
+        ctx['search'] = lambda query: '`%s`' % query
+
+        return ctx
+
+
+def _render_all():
+    DOC = InfoPageSet(OfflinePage)
+    for pagename, page in DOC.all_pages('en'):
+        page.render()
+    return DOC
+
+
+def _render_all_with_flask_ctx(base_url):
+
+    DOC = InfoPageSet(InfoPage, base_url)
+
+    # The url_for functions in the jinja templates need all routes to be
+    # registered in the Flask app.
+
+    settings['server']['secret_key'] = "x"
+    from searx.webapp import app
+
+    # Specify base_url so that url_for() works for base_urls.  If base_url is
+    # specified, then these values from are given preference over any Flask's
+    # generics (see flaskfix.py).
+
+    with app.test_request_context(base_url=base_url):
+        for pagename, page in DOC.all_pages('en'):
+            page.render()
+
+    # The searx.webapp import from above fires some HTTP requests, thats
+    # why we get a RuntimeError::
+    #
+    #     RuntimeError: The connection pool was closed while 1 HTTP \
+    #       requests/responses were still in-flight.
+    #
+    # Closing network won't help ..
+    #   from searx.network import network
+    #   network.done()
+
+    # waiting some seconds before ending the comand line was the only solution I
+    # found ..
+
+    time.sleep(3)
+    return DOC
+
+
+if __name__ == '__main__':
+    sys.exit(main())
diff --git a/setup.py b/setup.py
index ee208f23a..ffcdaf034 100644
--- a/setup.py
+++ b/setup.py
@@ -58,7 +58,8 @@ setup(
             '../requirements.txt',
             '../requirements-dev.txt',
             'data/*',
-            'help/*',
+            'info/*',
+            'info/*/*',
             'plugins/*/*',
             'static/*.*',
             'static/*/*.*',
diff --git a/tests/unit/test_webapp.py b/tests/unit/test_webapp.py
index 872b8d014..6385d187d 100644
--- a/tests/unit/test_webapp.py
+++ b/tests/unit/test_webapp.py
@@ -177,10 +177,14 @@ class ViewsTestCase(SearxTestCase):
 
         self.assertIn(b'<description>first test content</description>', result.data)
 
-    def test_about(self):
-        result = self.app.get('/help/en/about')
+    def test_redirect_about(self):
+        result = self.app.get('/about')
+        self.assertEqual(result.status_code, 302)
+
+    def test_info_page(self):
+        result = self.app.get('/info/en/search-syntax')
         self.assertEqual(result.status_code, 200)
-        self.assertIn(b'<h1>About SearXNG</h1>', result.data)
+        self.assertIn(b'<h1>Search syntax</h1>', result.data)
 
     def test_health(self):
         result = self.app.get('/healthz')