Describe your use-case which is not covered by existing documentation.

Hi,

As I was trying to set up the PR comment plugin on my Jenkins setup, I stumbled on the fact that (somewhat related to #20) I didn't get any triggers because I didn't use a "Discover pull request ..." behavior for my project. Instead I was using "Discover branches".

Since it seemed non-obvious to me that there was a hard requirement on the discovery behavior, I think it would be worthwhile to document this in the README file, and maybe add some more logs in that area.

Will you be open to a pull request documenting/logging this fact?

Thanks

Reference any relevant documentation, other materials or issues/pull requests that can be used for inspiration.

No response