Play code to make a MKS MINI12864 V2.0 work with a raspberry pi pico

This uses u8g2, and encoder-pio from pimoroni, using the cpp pico-sdk.

To get u8g2 to work, the CMakeLists.txt is patched to properly include it as a cmake project Then the functions for the SPI interface were created and it works OK.

See https://reprap.org/wiki/MKS_MINI_12864 for EXP1/EXP2 pinout.

Be sure to use 3.3volts instead of 5volts otherwise you might damage your pico.

• A hello snowman!
• Move the snowman left/right using the rotatry encoder
• Click the encoder to reset snowman to position 0
• Click the reset button to reset the Pico.