Add Marlin firmware. Has initial configuration for CoreXY and 1 servo.

Update CAD file with improved clearances for Pilot G2 cartridge clearances after first print.

Marlin Firmware/buildroot/bin/restore_configs

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+git checkout Marlin/Configuration*.h 2>/dev/null
+git checkout Marlin/src/pins/ramps/pins_RAMPS.h 2>/dev/null
+rm -f Marlin/_Bootscreen.h Marlin/_Statusscreen.h