Add Textured Object Example

[KTStephano]

We need an example of applying textures to game objects inside of src/application. Consider the following code:

Rectangle2D rect = new Rectangle2D(250,250,100,100,1);
rect.addToWorld(); // Make sure to add it!

This will add a new 2D, untextured rectangle to then world. There are methods inside of Rectangle2D to apply textures, so we want to show those being used.