Now I've tried to find something about it in the internet, searching in both, the GRBL config.h and pin_map.h and the official adafruit Shield Library, but I can't get through it.
I want to use the shield to controll two Stepper Motors for the x-axis and the y-axis,
but GRBL in "the plug'n'play" configuration can only work with two drivers for each Stepper.
I hope someone could help me, because my whole project stands still and it's really important for me to get it ready.