This updates our docs and release notes to use beanbag-docutils 2.2, and

to generate our JSON builds using our enhanced JSON writer and metadata

extensions, which provide more optimized builds for our website and

better SEO/social media integration.
Along with this update, there's a fix to explicitly run

reviewboard/manage.py with Python 3, which helps with automating doc

building in a mixed Python version environment.

Successfully built the manual and release notes with the new JSON writer.