Add a pre-commit hook to expand relative ticket refs to absolute

[bswck]

The hook would possibly change commit messages to ensure absolute ticket refs.

E.g.

• #27 → jaraco/skeleton#27, if we commit in skeleton,
• #27 → jaraco/tempora#27, if we commit in tempora.

Addresses commit integrations mismatch.

[jaraco]

Yes, that sounds wise!

I'm a little worried about a pre-commit hook, because it requires the developer to have the hook installed (which in turn requires the developer to have the tool installed somewhere) and doesn't affect contributions through GitHub. What I'd like more is something like branch protection that would reject a push that mentions a bare issue number.

[Avasam]

I'd love to see this as a proejct-wide, file-extension-agnostic check too ! It's an issue when working in forks. It would also make it easier to copy the issue reference outside the repo.
And yeah, doesn't have to be pre-commit.ci to be autofixable #109 (comment)
However, I can't think of any existing tool to be leveraged that I use other than pre-commit (the tool, not the git hook) which runs on all files. So it might have to be standalone.

A CI check w/o autofixes could probably easily be done with a grep script.

Btw I'm using https://marketplace.visualstudio.com/items?itemName=dt.ghlink to make those actual clickable links in VSCode