[New Feature]: Auto-push to PyPI

**Checked for duplicates**

Yes - I've already checked

**Alternatives considered**

Yes - and alternatives don't suffice

**Related problems**

We don't have CI/CD set up for this repository.

**Describe the feature request**

Every push to `main` should:
1. Create a release / CHANGELOG update
2. Build the package
3. Send the updated package to PyPI