App sync code, handles button presses from mixer and syncs changes from VM. Included python code from the mixer. Some other PCB changes, but still needs improvements

ControlMixerPython/boot.py

@@ -0,0 +1,12 @@
+import board
+import digitalio
+import usb_mixer
+recovery_pin = digitalio.DigitalInOut(board.D3)
+recovery_pin.direction = digitalio.Direction.INPUT
+recovery_pin.pull = digitalio.Pull.UP
+
+if recovery_pin.value == True:
+    print("Booting normal mode")
+    usb_mixer.initUsb()
+else:
+    print("Booting recovery mode")