Feature request: Expose git information

[nbigaouette]

I like to include git information in my builds. So for that I shell out at the top of my justfile to git to set variables:

git_commit_short := `git rev-parse --short HEAD`
git_commit_full  := `git rev-parse HEAD`
git_branch_name  := `git branch --show-current` # Requires git 2.22

(and potentially others)

This requires:

1. git is installed
2. a subshell

I try to minimize the amount of subshelling I do as to try to prevent cross platform issues (looking at you powershell).

Using gix/gitoxide (https://github.com/Byron/gitoxide/) would probably work out to get that information natively in Rust.

[casey]

This would be cool, but it doesn't seem worth including git/gitoxide in just, which are large dependencies which would increase build time and executable size.