1. Adds docs for working across models and to cover Brian's questions  about SHA1 sums.
1. Adds docs for working across models and to cover Brian's questions
 about SHA1 sums.

voutilad/courtlistener,Andr3iC/courtlistener,shashi792/courtlistener,wmbutler/courtlistener,Andr3iC/courtlistener,voutilad/courtlistener,wmbutler/courtlistener,wmbutler/courtlistener,brianwc/courtlistener,brianwc/courtlistener,brianwc/courtlistener,brianwc/courtlistener,wmbutler/courtlistener,wmbutler/courtlistener,shashi792/courtlistener,Andr3iC/courtlistener,shashi792/courtlistener,Andr3iC/courtlistener,Andr3iC/courtlistener,voutilad/courtlistener,voutilad/courtlistener,shashi792/courtlistener,brianwc/courtlistener,shashi792/courtlistener,voutilad/courtlistener