I would find it useful to create a warning annotation instead of an error

[jasonleenaylor]

In our project we want to encourage good format commit messages, but not have a strict rule for not merging them.

In most situations we would not accept the pull request if the message was bad, so we want a warning to draw reviewers attention. However if the issue is that a single line in the message is only a character over the limit, or if there are extenuating circumstances we would like to be able to allow the reviewer to just merge.

If there was an option in this library that allowed us to change the severity we would certainly use it.

I don't know if this is widely useful.