Summary:
Take all the issue type documentation in the website and add it to infer
itself so it can generate the website (see further diffs).
I mostly generated this diff by writing a script to call from `utop`
with various file lists to do most of the heavy lifting for me and make
sure I didn't forget any issue types: P132800781
Reviewed By: ngorogiannis
Differential Revision: D21934372
fbshipit-source-id: f3ea8c566