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/pins_set

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+IFS='/' read -r -a PINPATH <<< "$1"
+DIR=${PINPATH[0]}
+NAM=${PINPATH[1]}
+PIN=$2
+VAL=$3
+
+SED=$(which gsed sed | head -n1)
+eval "${SED} -i '/^[[:blank:]]*\(\/\/\)*[[:blank:]]*\(#define \+${PIN}\b\).*$/{s//\2 ${VAL}/;h};\${x;/./{x;q0};x;q9}' Marlin/src/pins/$DIR/pins_${NAM}.h" ||
+(echo "ERROR: pins_set Can't find ${PIN}" >&2 && exit 9)