Create Stub File for Type Annotation

[diegostammer]

Using VSCode with pylance plugin in strict mode generate a lot of errors about missing type annotation.
The request is to create a stub file (*.pyi) to document every type of constants, methods, functions, etc.

https://www.python.org/dev/peps/pep-0484/
https://www.python.org/dev/peps/pep-0561/

[sampsyo]

Cool; happy to accept a PR if anyone wants to write these.