Docs: update for RGBW neopixel

[microbit-mark]

Doc update to include support for RGBW Neopixels. I haven't tested this on hardware, so making an assumption that the values are in the order written eg np[0]= (R, G, B, W) as opposed to GRBW which I think is the default for NeoPixelsand we order them here https://github.com/microbit-foundation/micropython-microbit-v2/blob/6a4b97ffce97a41a593e77553a82e24e59b7107c/src/codal_port/modules/neopixel.py#L19

[microbit-carlos]

V2 also has fill and clear, could you check if those are available for V1 as well?
https://github.com/microbit-foundation/micropython-microbit-v2/blob/6a4b97ffce97a41a593e77553a82e24e59b7107c/src/codal_port/modules/neopixel.py

[microbit-mark]

V1 has clear and show. V2 has clear, write, fill, show

[microbit-mark]

I've updated to add the V2 methods in 9641853

Not sure on how best to present write() as I think it is equivalent to show().

Also not sure on how to present arguments for fill(). Is fill((r,g,b)) okay or should it be n,n,n or better to show the format in the description?

[microbit-carlos]

Not sure on how best to present write() as I think it is equivalent to show().

Yeah, they are equivalent. The current text is good, although if you need to edit the file anyway I might remove is available as part of the RGBW implementation and, just mentioning that they are equivalent is good enough.

Also not sure on how to present arguments for fill(). Is fill((r,g,b)) okay or should it be n,n,n or better to show the format in the description?

Showing the tuple would be difficult, as the length depends on how many bytes per pixel. I think it's fine to just name the argument color, as done in the python source code, and then in the description mention that it has to be a tuple of the same length as the number of colours per pixel, as configured in the constructor.

[microbit-carlos]

Perfect, thanks Mark!
Ready for merge 🎉