Move all the stuff to chaplinjs.org from README.

[Preview](https://github.com/chaplinjs/chaplin/tree/topics/move-stuff-from-readme#an-application-architecture-using-backbonejs). Promote [our site](http://chaplinjs.org) for all things.

1. Keeping duplicate info in both places can be painful.
2. Users won’t need to visit our repo unless they want to report issues etc.
3. This will greatly improve our marketing.
4. Things that are really relevant to GitHub repo (e.g. building / running tests) are still there.