WASD Scroller por Restlr

This is my first add-on, it allows you to scroll pages with W, A, S, D and increase ore decrease scroll speed with Q and E. Pretty great for reading if you have a faulty mouse. Not much to say about it right now. If I get any ideas on how to expand it, I will in the future. For now, let me know any about any bugs you encounter with this add-on.