[documentreview] Document the process for handling review comments at transitions

From @nigelmegitt (originally at https://github.com/w3c/Guide/issues/276):

As a general point, as per w3c/w3process#130 it would be good to document the process for handling review comments, and what kinds of responses are likely to result in a transition request being declined.

For example, if a responder says "I don't like the colour of the text in this document" and the WG ignores the comment, not even sending a response, is that okay? Or at the other end of the scale, if a commenter raises a detailed technical point, the WG considers and responds, and then the commenter remains unhappy with that response, is that okay?

What level of tracking of responses is required and what is merely good practice?

Start by reading the guidance referenced in w3c/w3process#130 and the original discussion at w3c/Guide#276. Define the expected handling, response, and tracking requirements for review comments, including when a transition request may be declined. Done means the process and examples are documented clearly enough to answer the questions raised here.