Move documentation to docs.astral.sh/ruff (#7419)

## Summary

We're planning to move the documentation from
[https://beta.ruff.rs/docs](https://beta.ruff.rs/docs) to
[https://docs.astral.sh/ruff](https://docs.astral.sh/ruff), for a few
reasons:

1. We want to remove the `beta` from the domain, as Ruff is no longer
considered beta software.
2. We want to migrate to a structure that could accommodate multiple
future tools living under one domain.

The docs are actually already live at
[https://docs.astral.sh/ruff](https://docs.astral.sh/ruff), but later
today, I'll add a permanent redirect from the previous to the new
domain. **All existing links will continue to work, now and in
perpetuity.**

This PR contains the code changes necessary for the updated
documentation. As part of this effort, I moved the playground and
documentation from my personal Cloudflare account to our team Cloudflare
account (hence the new `--project-name` references). After merging, I'll
also update the secrets on this repo.

.github/workflows/docs.yaml

@@ -52,4 +52,4 @@ jobs:
           apiToken: ${{ secrets.CF_API_TOKEN }}
           accountId: ${{ secrets.CF_ACCOUNT_ID }}
           # `github.head_ref` is only set during pull requests and for manual runs or tags we use `main` to deploy to production
-          command: pages deploy site --project-name=ruff-docs --branch ${{ github.head_ref || 'main' }} --commit-hash ${GITHUB_SHA}
+          command: pages deploy site --project-name=astral-docs --branch ${{ github.head_ref || 'main' }} --commit-hash ${GITHUB_SHA}

.github/workflows/playground.yaml

@@ -44,4 +44,4 @@ jobs:
         with:
           apiToken: ${{ secrets.CF_API_TOKEN }}
           accountId: ${{ secrets.CF_ACCOUNT_ID }}
-          command: pages publish playground/dist --project-name=ruff --branch ${GITHUB_HEAD_REF} --commit-hash ${GITHUB_SHA}
+          command: pages publish playground/dist --project-name=ruff-playground --branch ${GITHUB_HEAD_REF} --commit-hash ${GITHUB_SHA}