Proposal: Add review tags to patch review workflow.

[Simon Marchi]

> They were followed by discussion and some changes, AFAIR.  Also, the
> original post was quite long, so I hoped for a concise version akin a
> cookbook.
I just re-read the thread and I didn't find any changes to the proposal
in the original post.  Maybe some precisions.  In any case, Bruno will
update the wiki, it should be a short and sweet section.  It doesn't
need to explain all the rationale like the original post did.

Simon