Properly document the library

[paltman]

There have been a lot of features added since the initial pass at documenting this library. Bring things up to date.

[powerspowers]

Is there a fragments example anywhere on the web? I want to return the html to append to an element + also return a value via a fragment to update another elements value

[paltman]

@powerspowers https://github.com/eldarion/eldarion-ajax-demo/blob/master/demo/views.py#L14-L27