In the past, some files were tested with the standard profile, others with a
profile in which most of the messages were switched off ... some files were not
checked at all.

- ``PYLINT_SEARXNG_DISABLE_OPTION`` has been abolished
- the distinction ``# lint: pylint`` is no longer necessary
- the pylint tasks have been reduced from three to two

  1. ./searx/engines -> lint engines with additional builtins
  2. ./searx ./searxng_extra ./tests -> lint all other python files

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

To reproduce the issue set base_url::

    diff --git a/searx/settings.yml b/searx/settings.yml
    index 841457b5e..4e282cb61 100644
    --- a/searx/settings.yml
    +++ b/searx/settings.yml
    @@ -72,7 +72,7 @@ server:
       bind_address: "127.0.0.1"
       # public URL of the instance, to ensure correct inbound links. Is overwritten
       # by ${SEARXNG_URL}.
    -  base_url: false  # "http://example.com/location"
    +  base_url: "http://example.com/location"
       limiter: false  # rate limit the number of request on the instance, block some bots

and build the docs::

    $ make docs
    SPHINX    HTML ./docs --> file:///800GBPCIex4/share/SearXNG/dist/docs
    DOCS      build build/docs/includes
    Traceback (most recent call last):
      File "searxng_extra/docs_prebuild", line 85, in <module>
        sys.exit(main())
      File "searxng_extra/docs_prebuild", line 31, in main
        f.write(page.content)
      File "/usr/lib/python3.8/contextlib.py", line 120, in __exit__
        next(self.gen)
      File "searxng_extra/docs_prebuild", line 81, in _instance_infosetset_ctx
        return DOC
    NameError: name 'DOC' is not defined

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

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

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>