atmel-samd: Default to code.txt instead of main.py (main.py will still work on its own.)
atmel-samd: Default to code.txt instead of main.py (main.py will still work on its own.)

adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/micropython,adafruit/circuitpython,adafruit/micropython,adafruit/circuitpython,adafruit/micropython,adafruit/micropython,adafruit/micropython