Adding Tutorial

Today, I added the tutorial to the app. I included 3 sections: general info, controls, and menu buttons explained. I used the ScrollPane class (in Scene2d UI) that Jiho figured out to make it a scrolling window. This is updated on the website version that can be found here:

http://www.pages.drexel.edu/~njw59/

Below are some screenshots showing the content of the tutorial window.