More informative commit mesages

[Hritik14]

Commit messages for our project are not very informative.
Possibly we should use the same approach as the kernel and reject commits without a message body.
A pre-commit hook could do this job.

via https://github.com/nexB/vulnerablecode/wiki/WeeklyMeetings#meeting-on-thursday-2021-07-15-at-1200-utc