Add publish to PYPI workflow

[dpgraham4401]

Hi Again!

So we talked about this very briefly in #38. If you're still open automating the release to PyPi this GitHub Action workflow should do the trick. It's almost the stock workflow from the GitHub marketplace so nothing special.

It run every time you publish a release on GitHub and only requires 1 environment variable/secret which is your PYPI API key saved as "PYPI_API_TOKEN" under the autotiling's repo settings. I'm happy to help if you're unfamiliar with any part of this process.

I tested it using https://test.pypi.org which can be found here https://test.pypi.org/project/autotiling/ (i'll delete when this pull request is closed).

Talk when you're back from vacation, cheers!

[nwg-piotr]

I added a token as below:

Permissions: Upload packages
Scope: Project "autotiling"

and saved it in the autotiling repo secrets:

Hope this is what you meant.

[nwg-piotr]

It seems to work. Thank you!