## Summary
This approach is based on https://github.com/PrefectHQ/docs. Rather than
publishing docs in the uv repo, we push to an independent repo that's
used solely to house the docs. In Prefect's case, this allows them to
publish versioned documentation (we should do that too). For us, though,
the benefit is that we can publish the Ruff and uv docs as a single site
(docs.astral.sh).
Prefect clones the source repo and builds the documentation from the
`docs` repo (i.e., the action runs in the `docs` repo). In our case,
I've instead set it up such that the action runs in `uv` (and later in
`ruff` too), clones the `docs` repo, and puts up a PR in that separate
repo. Because of these requirements, we have to use a PAT rather than a
deploy key (as PATs cannot do GitHub-specific things like create PRs --
they can only operate over the Git CLI).
See: https://github.com/astral-sh/docs/pull/2.
## Summary
We want to have consistency between the Ruff and uv documentation for
the upcoming release. We don't love the Ruff docs, but we'd rather have
consistency and then work towards improving them both, rather than have
two very-different documentation sites that both have weaknesses.
The setup here is simpler than in Ruff as: (1) we don't yet generate any
docs from Rust and (2) we don't try to reuse the README in the uv
documentation (which adds a lot of complexity in Ruff). So the change
here is mostly a 1-to-1 port to MkDocs.
## Test Plan
