Switch to openstackdocstheme 2.2.1 and reno 3.1.0 versions. Using
these versions will allow especially:
* Linking from HTML to PDF document
* Allow parallel building of documents
* Fix some rendering problems

Update Sphinx version as well.

Disable openstackdocs_auto_name to use 'project' variable as name.

Change pygments_style to 'native' since old theme version always used
'native' and the theme now respects the setting and using 'sphinx' can
lead to some strange rendering.

openstackdocstheme renames some variables, so follow the renames
before the next release removes them. A couple of variables are also
not needed anymore, remove them.

See also
http://lists.openstack.org/pipermail/openstack-discuss/2020-May/014971.html

Change-Id: I5f985549671e3b4f8c438f247fae0818d25b21f5

Addressing feedback from
https://review.opendev.org/675762 . These comments are wrong
with current openstackdocstheme, so remove them completely.

Change-Id: Ibfb3a2e37ea5b89ce81caed3e4884ee077e0d967

Use sphinx-build and cleanup unused config.
Switch to openstackdocstheme 1.20.0 and remove obsolete settings from
conf.py files.

Update some RST files, they had wrong indentation.

Change-Id: Iaad2841db809f8a343fb8b1031cf8d0587d70442

Release notes are version independent, so remove version/release
values. We've found that projects now require the service package
to be installed in order to build release notes, and this is entirely
due to the current convention of pulling in the version information.

Release notes should not need installation in order to build, so this
unnecessary version setting needs to be removed.

This is needed for new release notes publishing, see
I56909152975f731a9d2c21b2825b972195e48ee8 and the discussion starting
at
http://lists.openstack.org/pipermail/openstack-dev/2017-November/124480.html
.

Change-Id: I594c14139dd8a3b313e95898ff86508fc7a40878

Update to use current openstackdocstheme everywhere instead of
oslosphinx, remove now obsolete settings.

Change-Id: I812f72ebf9fb4d96b1031880c44596833da9d384

Releasenote translation publishing is being prepared. 'locale_dirs'
needs to be defined in conf.py to generate translated version of the
release notes.

Note that this repository might not get translated release notes - or
no translations at all - but we add the entry here nevertheless to
prepare for it.

Change-Id: Iace1593dff20324b86c7245c2217d51d77d9a465

Add renote to automatically generate release notes - the same way other
OpenStack projects do it.
For details see
http://lists.openstack.org/pipermail/openstack-dev/2015-November/078301.html

Change-Id: I9789c5e21d8594593fc5536562a01644c6d63eef