Create tool to facilitate automatic creation of git tags for new XEP releases

[horazont]

Summary

In order to find specific revisions more easily in the git tree, the Editor has started to manually tag the commits which introduce a revision block using tags of the format xep-NNNN-vX.Y.Z.

Creating those tags manually is error-prone.

Work proposal

Given two git commits (the PR head and the merge base between the PR head and the current main branch), the tool should iterate until it finds a commit which adds a revision block for any XEP (it may do so by running the generation tooling for xeplist.xml for each revision and comparing the output).

The tool should emit the resulting tags and the associated commit IDs in a machine-readable format.

Requirements

• SHOULD NOT validate that no further changes happen to a document after the most recent tag in the commit range.

  This is left for a separate validation step.

• MUST output a machine-readable format

• SHOULD help human users by adding commit titles to the machine-readable format in an unambiguous way