Jon,
Agree with you here.
Designs are up on the Trello board for now. I don't know that we are posting them anywhere else for apps.
Regarding the edit summary -
We decided to make this a regular input field with tags as suggestion, so a new user isn't quite lost about what to say here.
Along with providing help at the start, having these in tag/autocomplete form makes it faster so a user doesn't have to type them in or even wonder how to describe their small change.
Key things the guide text needs to do is
-Explain when and why an edit summary is useful
-Provide some quick actionable examples
-If you added key information, or edited a large amount, provide specificity about what you did.
Thanks
Vibha