Configuration file entries for stubgen

[holmesv3]

Feature

Add configuration file options to control stubgen.

Pitch

The mypy stubgen docs indicate there are several command line options to configure stub generation. It surprises me that those aren't able to be configured from a table in the pyproject.toml (or other config option) in a section like [tool.mypy.stubgen] or something. I'm lazy and since I use the same options and module(s) every time I run I'd like to be able to set those in a configuration file and just run stubgen.