[CiaranOMara]

The reusable workflow tag.yml moves each major tag, such as v1, to the newest release of its major version, vX.Y.Z, by version, for a repository that callers follow by its major tag, such as one of reusable workflows. It follows whatever version tags exist, whoever made them, TagBot or a maintainer, and whenever it runs: on version tags pushed, on TagBot's completion, whose GITHUB_TOKEN tags start no workflow, daily, and by hand. A major tag already at its newest release stays, an older version's tag doesn't move it, pre-releases are left out, and annotated tags count at their commits. It moves the tags with the ReleaseFlow app's token, or else RELEASEFLOW_TOKEN, or else the job's own token.

This repository's TagBot now tags releases vX.Y.Z, with tag_prefix: NO_PREFIX and the ReleaseFlow app's token, in place of ReleaseFlow-vX.Y.Z, and Self-Tag.yml moves v1 to the newest; so callers following v1 get a release once ReleaseFlow's is registered and tagged, never one whose tag doesn't exist yet. The README describes the workflow beside TagBot, the environment's rules for the default branch and tags, and the release's steps. The tests run the step in a repository with version tags, with a stand-in for gh.