Hi Christian -
thank you for your work on the xqdoc files (and the link to the xquery used for generating them)!
The current state of XQuery plugins for the JetBrains/IntelliJ IDEs has changed a bit since I added the IDEA documentation to the wiki. Grzegorz Ligas' XQuery Support plugin has been forked by the talented developers at OverStory, with lots of MarkLogic-specific features added. Reece Dunn also has been working on an XQuery plugin that takes a slightly different approach: rather than focusing on one implementation, Reece is working on a plugin that provides broader language support. The very minor work that I've done has been for Reece - I'm (slowly) adding implementation builtin function signatures that will be used by his plugin to provide improved static analysis.
I hope that provides a bit of information regarding news with XQuery/JetBrains plugins.
Best,
Bridger