PEP about multiple dispatch and typing.overload

Hi there! I made a very early draft of a PEP that tries to make multiple dispatch work with `@typing.overload` to get type checkers and code editors support. It would be great to have the feedback of the maintainers on this :) The draft PEP: https://github.com/gabrieldemarmiesse/PEP-draft-multiple-dispatcher The discussion: https://discuss.python.org/t/multiple-dispatch-based-on-typing-overload/26197/1