(🎁) Add a "raise issue on mypy" button, or add a link to mypy github

[KotlinIsland]

Often times I want to create a gist of what I have in mypy-play and raise a github issue on mypy.

A link would be highly appreciated 😀. If you don't like the sound of a link to raising an issue, a link just to the mypy github would be just as based.