Added modals to clean up the class descriptions, created simple icons for the ruby and js classes.

Added modals for just the JS and Ruby class, cleaned up some of the markup. I don't have a working ruby environment on my workstation PC, so I had changed the <%= image_tag %> to good ol' html <img> markups.

Icons were done in Illustrator, let me know if you need the actual vectors. Couldn't find a cute logo to trace for .js...