Collect more examples of reviews for editors

[maelle]

With some words explaining why the example can be useful.
Could be used to have a few examples of "tough but constructive" reviews for instance.
The list would clearly state it's not exhaustive.

[noamross]

One good tough-but-constructive example: the part of this review suggesting a re-write of the vignette: ropensci/software-review#191 (comment)

[mpadge]

Another good example is for the slopes package, which ended up being fundamentally redesigned in response to the reviews. All reviews/reviewers were at all times entirely constructive, which seems to have played a major role in motivating the authors to embark on such a major overhaul. Comments such as, "this package does not ..." or "has not ..." were invariably followed by constructive suggestions for what could be done (there are, for example, several in one of the first reviews).