ci: automatically create ansible-documentation PR from release workflow

[gotmax23]

Ideally, we should set up this workflow to automatically create an ansible-documentation PR to copy over the release notes. We'll probably need to set up a bot user for this. I'll give it some more thought and add a follow up comment with potential ways to implement this.

[gotmax23]

We also have ansible/ansible-documentation#121 which takes a different approach. I'm not sure about the current state of that PR; I know there's been a lot of back-and-forth. @anweshadas, @webknjaz, do you have any thoughts about which approach makes the most sense or how we can best implement an approach like what's suggested here that doesn't require manually triggering a workflow in the other repo?