[feature request] Wasavi integration or something along those lines

[damaru2]

wasavi is an extension that transforms any text area in any website into a vi editor. Of course, it cannot transform other extensions' text areas. As a user, I like to use hypothesis to annotate things about scientific papers I read, and I need to write latex code in most cases, which is a bit cumbersome task and it would be alleviated if one could use a vi editor or something similar