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.

crates/ruff_dev/src/generate_options.rs

@@ -1,6 +1,6 @@
 //! Generate a Markdown-compatible listing of configuration options for `pyproject.toml`.
 //!
-//! Used for <https://beta.ruff.rs/docs/settings/>.
+//! Used for <https://docs.astral.sh/ruff/settings/>.
 use itertools::Itertools;
 use ruff_workspace::options::Options;
 use ruff_workspace::options_base::{OptionEntry, OptionField};

crates/ruff_dev/src/generate_rules_table.rs

@@ -1,6 +1,6 @@
 //! Generate a Markdown-compatible table of supported lint rules.
 //!
-//! Used for <https://beta.ruff.rs/docs/rules/>.
+//! Used for <https://docs.astral.sh/ruff/rules/>.
 
 use itertools::Itertools;
 use strum::IntoEnumIterator;