Update the Review Board 3.x code reference and add links to Djblets docs.
Review Request #10828 — Created Jan. 17, 2020 and submitted
This adds a number of modules to the Review Board 3.x codebase docs,
helping to find useful and important modules when working with the
This still leaves out a number of modules, mainly those that are more
internal and less useful to expose to third-parties, though it's a fine
line at times.
Some of the module sections now link to the Djblets docs as well,
helping people get a more complete picture of the various parts.
There are also docstring fixes for some modules that weren't previously
included and now break. These modules are still largely using legacy
docstring formats, though. Only the docstrings containing errors were
Built the docs. Checked for errors and bad links.