Fluid 5439: More documentation for panels.

@cindyli, the original page that this links to is in the fluid wiki space (i.e. not the documenation). Given that it's more of a working document describing our learning, I think it belongs in the fluid wiki space, and not in our new documentation. In fact, I'm not even sure that this page (i.e. this font icon tutorial page) should have a link to that wiki page...