Add type stubs (.pyi)

[justingrant]

Things to check first

• [x] I have searched the existing issues and didn't find my feature already requested there

Feature description

Are there any plans to add .pyi type stubs for this package, for use with pyright & mypy?

Use case

I'm new to typed Python (so I apologize if I'm not asking the correct question here!) but I'm mostly trying to figure out what to do with the errors that Pylance is showing me in VS Code complaining about missing type stubs.