Include Git SHA in font version string (name ID 5)?

For the projects I maintain, we currently make use of [`font-v`](https://github.com/source-foundry/font-v) to take the Git SHA for the current commit and include it in the version string, ending up with something like `Version 14.000;[b4d79111d]`, where in the sources the version is specified as 14.000.

Is this something we'd be interested in supporting in `gftools`, given that `font-v` is now unmaintained? I'd be happy to contribute it if so, be it as the default, an option, or an operation.

Let me know your thoughts!

Start by comparing the requested behavior with the linked font-v project and reviewing how gftools currently handles font version strings. Done means agreeing on whether Git SHA support belongs in gftools and defining its interface, including whether it is the default, an option, or a separate operation.

Written by the indexing model from the issue text.