Doc page improvements

I'm not really happy with the formatting on this page, particularly the version listing.  Ideally, we'd have a drop-down similar to what's on relish for the versions but I'm not sure how to do that.
I specifically put the API docs on top because I feel we should advertise them as the more primary/main docs.  We've gotten a lot of complaints about the relish docs and I think it's time to de-emphasize them.