A release-worthy change under a hidden commit type (ci:, chore:, docs:, …) ships no release — say so where the types are chosen

[TzuH-Hsu]

Problem

release-please only opens a release PR for feat, fix, perf, revert and breaking changes; ci, chore, docs, refactor, test, build, style are hidden types and produce nothing. #69 shipped the PR lint — a change every adopter sees in CI — as ci:, and release-please answered No user facing commits found … skipping. Nothing in skills/release-management or skills/branch-and-commit says which types release, or what to do when a hidden-type change must ship (a Release-As: X.Y.Z footer, which docs/setup/bootstrap.md mentions only for the first release).

Fix

• skills/branch-and-commit rule 3 ("pick the type deliberately — release-please reads it"): name the two groups.
• skills/release-management: a pitfall for "release-worthy change under a hidden type", with the Release-As: footer recipe — in the PR body, since squash_merge_commit_message=PR_BODY makes the body the commit message.

Acceptance

make verify green; this PR's body carries Release-As: 0.5.2 and release-please opens chore: release 0.5.2 from it.