Version 1.4.3

- added option to select an alternate HW SPI channel and/or SPI settings
- by method selectSPI(SPIClass& spi, SPISettings spi_settings) of driver base class GxEPD2_EPD
- by calling selectSPI before calling init() of display class
- or by calling extended init() method that has these parameters added
- tested with RPi Pico RP2040 using Good Display DESPI-PICO connection shield
- updated GxEPD2_Example to show use with DESPI-PICO
- DESPI-PICO: see https://www.good-display.com/product/393.html