There are about a dozen short documents that would really be useful that would not have to be written by Jules.
There’s that previous document I described, on threading and locking.
Even a few paragraphs on the new leak detector would be very enlightening to developers (it’s really useful and easy to use if you dig into it).
A page on how juce::String handles encodings and internationalization would have saved me reinventing the wheel a few months ago.
I’ve seen a lot of stuff on writing audio plug-ins on the forum that would be much clearer in one or a few documents.
There are several more. A wiki-style collaborative space where members could mark up a few documents on these matters might clarify things greatly for the new developer.