adds chat rooms

What it does: 
adds chats for specific documents

ToDos: 
write tests for chats
make chats persistent
add usernames

just to make sure, did you know i made a gulpfile? i didnt take out all of the script tags in index.html yet. i mightve forgot to tell everybody.

you'll need to add any new js files youve written to the gulp js command. let me know if that doesnt make sense. and you could go ahead and actually take out/comment out all of the script files in index.html after doing that, all of them except the first main.js file
the gulp js command concats all js files into one main.js file