Balance out the 'try it' and 'see it' blocks

What about something like this?

![see_it_refresh](https://cloud.githubusercontent.com/assets/124661/3465135/5fb91072-025e-11e4-9357-fd0821e7ab2d.png)


Just noodling a bit, threw in some more copy to try and flesh it  out a little and let the reader know what they are in for.  The instructions are osx specific, just started there since that's what I had.  Could confuse people.   Could do browser/os detection and try to get fancy, probably overkill.

ref gh-1636