Feature Request: User-specific strings to block

[jotoeri]

Hey Brian,

first thank you for this action! It is a really useful feature and very easy to use without manually digging into this. ❤️

I just recognized i sometimes use commit-prefixes as 'donotmerge!' to store some dirty stuff, that i don't want to get merged, but that even is no fixup (as there is no base-commit to squash into). So i thought it would be cool, if one could configure somehow for user-specific strings, that do additionally block the PR to get merged!?

Greets! :)
Jonas