use_git_pre_commit_script: Use a Script as git pre-commit hook
Description
Provide a pre-commit.d/ in ./git/hooks, a pre-commit hook that executes
scripts from that directory and copy the script_file there.
Usage
use_git_pre_commit_script(path, script_file)
Details
This might work only for proper git, not for packages like gert or
git2r.