Bump version to 0.812

Add Python script to build wheels using cibuildwheel (python#10096)

The contents are extracted from the current GitHub action definition:
https://github.com/mypyc/mypy_mypyc-wheels/blob/master/.github/workflows/build.yml

This is a fairly direct translation of the existing behavior. The
behavior should be identical to the current workflow.

The idea is to make this easier to maintain and easier to test
locally.

This should also make it easier to fix python#10074.

Bump version to 0.810

Bump version

Bump version to 0.790

Bump version to 0.782

Bump version to 0.781

Add docs for no_site_packages config option (python#8932)

Bump version to 0.770.

Bump version to 0.761

The 0.760 source tarball was not uploaded to PyPI; the only difference
in the 0.761 release is that it will (hopefully) be fully uploaded this
time.