Index page

[jzaefferer]

We don't yet have a proper index page. Will merge the work that currently goes into the api.jquery.com repo for that.

[jzaefferer]

Waiting for @kswedberg to implement somthing for Core API, then we can port that over here.

[kswedberg]

@jzaefferer I have index, category, and sidebar templates roughed in now. Not sure how much more needs to be done until I know how closely the design will match the one on pixelgraphics.

[jzaefferer]

The index page is looking reasonbly good now. Whatever is missing will apply to all API templates anyway.