Add a link back to the source of the beach image, which is CC-licensed

I'm super chuffed that you used one of my photos from last year on the scheduling page! It's licensed under [CC-BY-NC-SA](http://creativecommons.org/licenses/by-nc-sa/4.0/deed.en_US) though, which means you're welcome to use it but need to provide attribution. I've added a link back to the original.

I noticed none of the other photos on this page are attributed either, but they aren't mine so I'm not sure where they came from. You may want to add proper attribution for them as well.
Merge pull request #2 from rgrove/patch-1

Add a link back to the source of the beach image, which is CC-licensed