Various fixes & improvements

[Gadgetoid]

Round up of a few overdue fixes and quality of life improvements.

I've added some comments to the examples that should save future Pirate Audio users a little hassle. Thanks to Floyd for finally poking me to connect the dots. Watch his Fluid Synth build video here: https://www.youtube.com/watch?v=ilmhX1j-ENU

[Gadgetoid]

For users wanting to use multiple ST7789 boards, and who have found it's all suddenly rather broken, this is a "The Linux Kernel No Longer Lets You Share Pins" problem.

Fortunately we don't strictly need to share pins.

Using this branch it should be possible to pass in a pin object, in lieu of an int, and the ST7789 library will use that. I still need to whip up an example, but I stuck some ✨ Factory Functions ✨ onto ST7789 so you can share the same data/command pin like so:

dc = st7789.ST7789.get_dc_pin(pin)

display1 = st7789.ST7789(... dc=dc ...)
display2 = st7789.ST7789(... dc=dc ...)

I hasten to add that I need to dig up my breakouts and Breakout Garden and actually test these changes.