Add "trim" option for forward and reverse #10
Description
The problem is due to variation in motor speeds and possibly cant of the tracks, you rover could veer left or right when in forward or reverse. It would be nice to have a way to "trim" out the rover so it tracks in a straight line while driving forward or reverse.
One possible way to do this is to have a trim option that causes the forward or reverse control input to vary the speed of the left or right motor. Maybe a slider that is normally neutral meaning that the same power goes to each motor and then if you slide one way more power goes to one motor and less to the other... and sliding the other direction does the opposite... That is this slider could vary motor speed up to some small amount... like maybe 10% max, but allows you to bias one side with more power to compensate for other variables that cause it to drift in one direction or the other.