[@changesets/changelog-github] Contributor-only thanks option (skip thanks for repo maintainers)

The problem

@changesets/changelog-github currently renders every release line as

- [#210](…) [`4f75d34`](…) Thanks [@author](https://github.com/author)! - <summary>

For solo-maintained (or small-team) projects, that means every "Version Packages" PR reads "Thanks @maintainer! - …" on every entry, i.e. the maintainer is publicly thanking themselves. The existing disableThanks option is a blunt switch: it hides thanks for everyone, which then also silences the acknowledgement that outside contributors are supposed to get.

Proposed option

An allow/deny list, or a maintainers list, that suppresses the "Thanks @user!" chunk only when the resolved author matches one of the configured GitHub logins. Everyone else keeps their thanks. Rough shape:

"changelog": [
  "@changesets/changelog-github",
  {
    "repo": "org/name",
    "maintainers": ["castastrophe"]
  }
]

Semantics:

• When users (the joined "@a, @b" list built at changesets-changelog-github.esm.js:144) contains only logins from maintainers, drop the entire Thanks …! clause.
• When users mixes a maintainer with outside contributors, keep the full list — that credit is still meaningful.
• If users is empty (no linked commit/PR author), behavior is unchanged.

Backwards compatible: default maintainers to [] and the current output is untouched.

Alternative considered

Wrapping the package with a local changelog module that post-processes getReleaseLine's output and strips the maintainer's thanks with a regex. It works (see example wrapper), but it duplicates the option surface, adds a resolve step to .changeset/config.json, and every consumer that wants the same behavior has to write the same tiny wrapper. A first-class option would let projects express "the maintainer is us; only shout out real contributors" without a bespoke shim.

Willing to help

Happy to open a PR wiring this into packages/changelog-github/src/index.ts and the option validation in @changesets/config if the shape above is acceptable.