Publish docs automatically on release

[db9795]

Changes

Publish docs on release

publish-docs.yml can now also be called as a reusable workflow (workflow_call). release.yml calls it in a new publish-docs job, so the docs page in maptoolkit/docs is updated every time a version is published to npm.

• Runs only when changesets actually published (needs.release.outputs.published == 'true'), same condition as deploy-pages. The docs therefore always describe the version that is on npm, not unreleased README changes on main.
• workflow_dispatch still works for out-of-band doc fixes.
• Docs path and front matter stay in one place (publish-docs.yml).

README badges

Replaced the badges with versions that also work on the Maptoolkit docs page:

• NPM (version), License, GitHub
• License now links to the absolute GitHub URL instead of the relative LICENSE path, which was a dead link on docs.maptoolkit.com
• New GitHub badge, so readers of the docs page can find the repo

Notes

• Includes a patch changeset. Merging the resulting "Version Packages" PR publishes a new version, which also tests the new release → publish-docs chain.
• Requires the DOCS_REPO_TOKEN secret, which is already set up for the manual workflow.