Build Sphinx documentation

[veekaybee]

Is your feature request related to a problem? Please describe. No centralized docs!

Describe the solution you'd like To build Sphinx docs, we need to follow the repo structure and CI actions we've done for lm-buddy.

1. Follow the directions from sphinx-quickstart
2. Follow this for reference: https://github.com/mozilla-ai/lm-buddy/tree/main/docs
3. Add a GitHub action based on this one that builds the docs: https://github.com/mozilla-ai/lm-buddy/blob/main/.github/workflows/docs.yaml
4. Enable docs to be a public github page.

Describe alternatives you've considered A clear and concise description of any alternative solutions or features you've considered.

Additional context Add any other context or screenshots about the feature request here.

[veekaybee]

As part of this, we should make sure to separate docs tests/builds from app docs/builds.