Update sphinx to 4.0.0

[pyup-bot]

This PR updates sphinx from 3.5.4 to 4.0.0.

Changelog

4.0.0

=====================================

Dependencies
------------

4.0.0b3

* 9167: html: Failed to add CSS files to the specific page

4.0.0b2

* C, C++, fix ``KeyError`` when an ``alias`` directive is the first C/C++
directive in a file with another C/C++ directive later.

4.0.0b1

* 8917: autodoc: Raises a warning if function has wrong __globals__ value
* 8415: autodoc: a TypeVar imported from other module is not resolved (in
Python 3.7 or above)
* 8992: autodoc: Failed to resolve types.TracebackType type annotation
* 8905: html: html_add_permalinks=None and html_add_permalinks="" are ignored
* 8380: html search: Paragraphs in search results are not identified as ``<p>``
* 8915: html theme: The translation of sphinx_rtd_theme does not work
* 8342: Emit a warning if a unknown domain is given for directive or role (ex.
``:unknown:doc:``)
* 7241: LaTeX: No wrapping for ``cpp:enumerator``
* 8711: LaTeX: backticks in code-blocks trigger latexpdf build warning (and font
change) with late TeXLive 2019
* 8253: LaTeX: Figures with no size defined get overscaled (compared to images
with size explicitly set in pixels) (fixed for ``'pdflatex'/'lualatex'`` only)
* 8881: LaTeX: The depth of bookmarks panel in PDF is not enough for navigation
* 8874: LaTeX: the fix to two minor Pygments LaTeXFormatter output issues ignore
Pygments style
* 8925: LaTeX: 3.5.0 ``verbatimmaxunderfull`` setting does not work as
expected
* 8980: LaTeX: missing line break in ``\pysigline``
* 8995: LaTeX: legacy ``\pysiglinewithargsret`` does not compute correctly
available  horizontal space and should use a ragged right style
* 9009: LaTeX: "release" value with underscore leads to invalid LaTeX
* 8911: C++: remove the longest matching prefix in
:confval:`cpp_index_common_prefix` instead of the first that matches.
* C, properly reject function declarations when a keyword is used
as parameter name.
* 8933: viewcode: Failed to create back-links on parallel build
* 8960: C and C++, fix rendering of (member) function pointer types in
function parameter lists.
* C++, fix linking of names in array declarators, pointer to member
(function) declarators, and in the argument to ``sizeof...``.
* C, fix linking of names in array declarators.

3.5.5

==============================

Links

• PyPI: https://pypi.org/project/sphinx
• Changelog: https://pyup.io/changelogs/sphinx/
• Homepage: http://sphinx-doc.org/

[pyup-bot]

Closing this in favor of #220