Partially implements <https://issues.guix.gnu.org/66027>.
This will make it possible to track a merged commit back to its original
posting on the mailing list, and open the door to new opportunities such as
closing fully merged series automatically.
* Makefile.am (COMMIT_MSG_MAGIC): New variable.
(.git/hooks/commit-msg): New target.
* etc/git/commit-msg: New file.
* doc/contributing.texi (Configuring Git): Document Change-Id.
Series-changes: 3
- Clarify documentation text, as suggested by Simon
Change-Id: Ia92fa958eae600fdd4e180bad494c85db8bb4dd6
Reviewed-by: Simon Tournier <zimon.toutoune@gmail.com>
