fix </back> tag placement and update author to include MWF

@mamund Please review and merge.

This PR corrects the placement of the \<back/> tag to include \<section/> tags outside of it. It also adds updated author information. In general, adding authors changed page spacing. 

Seems new xml2rfc library has some nuances in how it formats things, e.g. now forces a blank line for organization on Leonard for some reason. Added blank spaces in various places too. I note a few peculiarities on the changed files with comments. I did not edit that out manually because I figured next person to run library might override that.

Also, updated the README with contributing instructions that I used to make these changes.