Add GitHub Actions CI for checking style, running tests, publishing Docker images, PyPI packages, and documentation.

[truskovskiyk]

Ensure all releases, style checks, and unit tests can be run via CI, blocking any PRs that fail CI.

For Docker packages, use: https://github.com/orgs/georgian-io/packages

For PyPI packages, use: https://pypi.org/

[benjaminye]

As a preamble for PyPI CI, we should add to the repo a PyPI Key. This can be done securely via Github Secrets.

[benjaminye]

Implementation Status
✅ Style Checks
✅ Publish to PyPI on Release; PR #121
✅ Publish to Container Registry; PR #122
🔴 Build and Publish Docs (blocked); See comment #111 (comment)