Notes:

Did the code for the servos, the robot is difficult to drive.

The right servo is backwards so I just flipped the map function to be 180 -> 0 and that worked.

I first made it just go forwards and backwards to test stability etc.

So this may be questionable(sketchy), I'm not exactly sure how this works - I didn't think, it was just intuition.

As you'll see in the code, each wheel is controlled by a combination of the x and y joystick movement.

So, we have it map now from 0 to 90 for x and y, this means when joystick is zeroed.

Both x and y output 45 which adds together in the next line and is sent to the servo as 90, aka no rotation.