Packaging / Release Action

[thinkl33t]

• Automatically push to pypi testing on push-to-main
• Automatically push to pypi on tag

Closes: #95

[jonathanmaw]

These changes look logical and line up with the documentation.
The test run looks like it's doing exactly what it's expected to.

I have as much certainty that this is doing exactly what is expected as is possible without actually trying to upload to the non-testing pypi.
Approved!