Run Zephyr on Micro Bit (source code)

= Run <Zephyr> on Micro Bit
{tag=Run Zephyr on X}

Docs: https://docs.zephyrproject.org/2.7.0/boards/arm/bbc_microbit/doc/index.html

Build worked:
``
west build -d build/microbit/hello_world -b bbc_microbit samples/hello_world
``
but flash failed:
``
west flash -d build/microbit/hello_world
``
Related: https://mattoppenheim.com/2018/06/24/using-udev-to-remove-the-need-for-sudo-with-the-bbc-microbit

The build also generates a .hex file by default, and we've tried to flash it manually with:
``
cp build/microbit/hello_world/zephyr/zephyr.hex /media/ciro/MICROBIT/
``
but we failed to see it do anything with <zephyr/blink_gpio.c>{file}, so not sure if the flashing was broken or if the code was broken, or if we didn't find the IO pins correctly.