Making a DifferentialDrive

A DifferentialDrive is a special type of system for a robot that gives it two independently-controlled wheels to move around. The XRPDrivetrain class already has one, but you might not understand how it works. Also, by doing this segment, you will practice how to use XRPMotors, which are a good stepping stone for other, more advanced motors you would see in FTC and FRC robots.