Add "common issues" doc to cover known workarounds

I'm happy to write a first draft of this if the maintainers would like it. But I don't want to put in the effort if it's not wanted.

I've run into two issues which really puzzled me in terms of what to do until I poked around in issues here. I'm sure there are others.

`hybrid_property` can't use the special magic of `property` in `mypy`, but #98 has a workaround seems to work. And #94 covers ways of getting `UUID(as_uuid=True)` to work.

It would be helpful (since these are not going to be fixed soon) if this library made these workarounds part of its docs. It could be done at the end of the readme or in a separate markdown doc linked in the repo.