Added driver and setup-example for ST7567s displays

[EnricoRoss98]

This driver allows the use of the nano-gui library on displays driven by ST7567s IC. Those have usually a resolution of 128x64 and are monochrome backlight LCD displays. Due to the similarities, these displays are basically drop-in replacements (except for changing the driver) for the famous SSD1306 IIC 128x64 OLED display, allowing a fast transition from 0.96" to 2.14" and from OLED to LCD.

[peterhinch]

This looks good, but please prepend constant names with an underscore:

_CMD_DISPLAY_ON          = const(0xAF)

This saves RAM at zero cost.

This is because Python creates a memory variable for globals unless they start with underscore. This caters for the case where someone issues from module import *.

[peterhinch]

Thank you.