- Update to 0.20.1:
* Include tox.ini and docutils.conf in the source package
* Docutils 0.20 is the last version supporting Python 3.7 and 3.8.
* Support Python 3.11 (patch #198 by Hugo van Kemenade).
* New functions `rst2…()` for use as "console_scripts" `entry points`_.
* Fix `previous_sibling()` method that led to invalid HTML in some cases
* Fix bug #463. Spurious comma in deprecation warning.
* Improved mock Sphinx module.
* `Transformer.populate_from_components()` now silently ignores
components that are not instances of `docutils.TransformSpec`.
* Accept author names with initials like ``A. Einstein`` in the "author"
`bibliographic field`_ instead of rising an error
* `DanglingReferences` ignores `citation_reference` nodes if the
"use_bibex" setting is active.
* New utility function `xml_declaration()`.
* `DependencyList.add()` accepts `pathlib.Path` instances.
* Support "mod" notation for modulo operation / modulus arithmetic.
* Wrap definition lists with "details" class argument in a

with the "id" and "class" values of the list node.
* Use dpub-ARIA role "doc-footnote__" (instead of ARIA role "note")
for footnotes.
* Do not load the `inputenc` package in UTF-8 encoded LaTeX sources.
(UTF-8 is the default encoding for LaTeX2e since 2018).
* Fix behaviour of the use_bibtex_ setting.
* Outsource parts of `depart_document()` to new auxiliary methods
`make_title()` and `append_bibliography()`.
* Drop ``\usepackage{fixltx2e}`` from template.
* Fix SetuptoolsDeprecationWarning: ``Installing '' as data is deprecated``
by adding data directories to package_data.packages list.
* Refactored tests to use common `unittest` idioms.