Add support for lgpio

[Stephen-Hamilton-C]

Unfortunately, RPi.GPIO doesn't work on Raspberry Pi 5 as discussed by this forum post. This pull request helps to resolve this by adding support for lgpio, an easy-to-translate replacement for RPi.GPIO. The new file, lgpio.py, is based on the gpio.py file with some modifications to accommodate the new library. Additionally, documentation is updated to acknowledge the new file.

I've tested this on my own Raspberry Pi 5 with a 16x2 LCD and it Works On My Machine™

[dbrgn]

I don't have access to a Pi 5, so maybe someone else can give this code a try to confirm it to be working?

There's also a lot of duplication between lgpio and gpio that could be abstracted away using a shared base class. But in practice it's probably fine as-is.

[dbrgn]

This should probably be 5+, right? (Assuming that the GPIO won't change again in the next version.)

Suggested change

	The main class for controlling GPIO (parallel) connected LCDs on Raspberry Pi 5
	The main class for controlling GPIO (parallel) connected LCDs on Raspberry Pi 5+

[Stephen-Hamilton-C]

How does adding or newer sound? e.g. The main class for controlling GPIO (parallel) connected LCDs on Raspberry Pi 5 or newer. 5+ to me almost sounds like a model number. I'm fine with 5+, but I'd rather be as clear as possible

[dbrgn]

Again:

Suggested change

	Note that if you are using a Raspberry Pi 5, you'll need to use this import
	Note that if you are using a Raspberry Pi 5+, you'll need to use this import

Also in a few other locations below.

[Stephen-Hamilton-C]

Just got back home from vacation - thanks for the notes. I'll address them on Monday

[Stephen-Hamilton-C]

There's also a lot of duplication between lgpio and gpio that could be abstracted away using a shared base class. But in practice it's probably fine as-is.

I could certainly do this for you if you'd like. Would you rather this be a separate pull request or leave it in here?