Earlier today I pushed a change that split this code up into multiple
repos, but that has proved to complicate things too much. So we're
back to a single repo, except the individual submodules are better
separated than they were before.
The README files need updating again; I will push them out soon.
Aside from splitting out the different modules, the sound code has
moved from from anki to aqt.
I've corrected some obvious issues, and we can fix others over time.
Mypy tests are currently broken, as adding the type hints has increased
mypy's testing surface.
