On the theme of code search, I have submitted a MediaWiki docset to the Dash user contributions repo, so you can also use it with Zeal[1], which looks like this [2, 3]. It includes collaboration diagrams and references/referenced by listings.
Obviously, as it's only from the core doxygen it doesn't include extensions, but I find it goes a long way to demystifying things. Because it's only built[4] manually and submitted manually, it's not bang up-to-date, but I have found it handy. Really it just provides a less clunky interface to doxygen's HTML
You can download the docset via the XML feed here (just paste this into Zeal's "Add Feed" button): https://zealusercontributions.vercel.app/api/docsets/Mediawiki.xml
You can also see a lot more user contributed docsets here: https://zealusercontributions.vercel.app
Cheers,
-- IL
[1] https://zealdocs.org/ [1] https://phabricator.wikimedia.org/F34943176 [2] https://phabricator.wikimedia.org/F34943177 [4] https://github.com/inductiveload/mediawiki_docset