Add comments/chapter work stat

[tykobrian]

I'd like an option to view the total comments made in a fic divided by the total number of chapters. For example, if a fic having 10 chapters has 100 comments, the comments to chapters ratio is 10:1 meaning on average there are 10 comments per chapter.

In my personal opinion, the number of comments posted per chapter or afic is a useful way to find good fics.

It's easy to just put kudos but it takes much more effort to make comments. Fics with higher comments per chapter ratio may have engaged more people enough to compel them to express their thoughts on the fic as comments. Then we can sort the fics having the highest "comments per chapter" ratio to find the most engaging fic.