Next level of gradual typing support #1160
Description
It'd be nice to have per-file typechecking levels for better gradual typing.
Sorbet does this via comments at the top of files and has the ability to do mass updates as well.
I could imagine a central config as an alternative (default level and exceptions).
RuboCop has a few ways of solving this same problem that might be worth looking at.
Taking the idea further, could solargraph act as a RuboCop plugin and inherit its approach?