History: AJAX

[philsturgeon]

This might be my backend brain kicking in, but the new history/backstory section in the introduction could be expanded a little with a paragraph or two on AJAX that explained we were kinda mushing some API-ish stuff in there and that gave clients some abilities to jQuery/realtime stuff in the frontend with the power of the backend, and all the headaches that brought on.

Or it could be larger and elsewhere.

Questioning the relevant @mbifulco but wanted to ask.