Fixed undo key for controllers.
Controllers are now fully supported
Removed the frag/+frag button for the undo option as it wasn't working for controllers
Moved the use/+activate key from the select option (by default F on PC and Square on Playstation controllers) to the undo option instead.
Updated the README to add controller support information and screenshot
Remove example values in the DVARs table to allow table to be displayed normally (example values column was out of the screen, a right scroll was needed to display it)
The Configuration section is used for the examples instead
