Enforce writing commit message bodies

[jhlegarreta]

Description

Frequently contributors do not write a commit message body, and it becomes difficult to see the rationale or benefit of the change, or the reason why a particular approach was chosen.

Impact analysis

Not writing a commit message body makes it difficult to understand past changes when navigating the git history, and any relevant exchange may remain only on the GitHub comments.

Expected behavior

We should enforce e.g. through a pre-commit hook writing a commit message body.

Actual behavior

Commit message bodies can be empty.

Versions

master.

Environment

Any.

Additional Information

Although we cannot ensure self-contained, complete message bodies, this will at least avoid empty commit message bodies.