Host docs on github pages

I think it'd be helpful to host rendered `stardoc` docs on a github pages site similar to the following:
- https://bazelbuild.github.io/rules_rust/
- https://bazelbuild.github.io/rules_nodejs/
- https://bazelbuild.github.io/rules_foreign_cc/

Any admin of the project can set it up in just a few clicks since the docs are already committed to the repo.

Verify the rendered stardoc documentation already committed to the repository, then review the GitHub Pages setup against the linked rules_* examples. Done means the repository's rendered docs are published and accessible from a GitHub Pages site.

Written by the indexing model from the issue text.