XML: Made "Douglas" and "Other" articles separate submenus instead of groups

This will allow us to have a "Random" button in the submenu
Added random features

Changed "special" attribute to "isExperiment
Added "Random" feature for Articles, Video, and Experiments. Random is accessible from both the submenus as well as browser.
Changed "Experiment" button name on "Pointers" page to "Do An Experiment"