Maybe read this after you've already looked at everything:

This program is kind of...unnecessarily complicated. It looks super
confusing because it has all these different files and it keeps interacting
with other code.

1. The driver presses a button, which is detected by a GenericHID that FIRST 
made for us. 
2. From there, it gets translated into a "request" by the controller
wrapper, and then, 
3. a Command finds out about this "request" and tells a part of
the robot to do what has been requested, and then,
4. that part of the robot tells a smaller part of the robot -- an individual 
motor controller -- to do something, and then
5. the RobotMap translates that motor controller into an actual port that
is connected to a motor controller, to tell that motor controller to make a 
motor do something.

A piece of user input goes through about five different steps before anything
happens.

This entire program could be rewritten so that there are no files
except the Robot file and the RobotMap file.