[Feature Request] Versioning when building from git





```
$ gnuclad
gnuclad 0.2.4
```

```
$ gnuclad
gnuclad HEAD
```
Use versioning like for AUR VCS pkgbuilds (without tags) https://wiki.archlinux.org/title/VCS_package_guidelines#Git

>   printf "r%s.%s" "$(git rev-list --count HEAD)" "$(git rev-parse --short HEAD)"

r105.0cac2b6
