Currently there's basically absolute 0 docs on job queue, only a stub from 2010 which is even wrong.
Some of the undocumented stuff to do include things like:
- https://gerrit.wikimedia.org/r/37481 – rMWa1e7329d8f1a: Use JobQueueGroup::singleton()
- https://gerrit.wikimedia.org/r/37459 – rETRN5fb37a5dded0: (Bug 42715) Add missing $id to TNJob
- ... (no idea how many).
Or maybe the documentation should be created only after the jobqueue code stabilises? It's changing very frequently in the last few months.