Add support for SK6812RGBW LED's

[jwillikers]

I want to use this crate, but can't with my SK6812RGBW LED's. Would it be possible to add support for this like is available in the smart-leds-rs/ws2812-spi-rs crate?

[LokleLama]

I plan on implementing it. Depending on my time I might have it as soon as end of 2024

[LokleLama]

@jwillikers I am sorry, I did forgett to check the pull requests. This feature has alredy been implemented by @Nashenas88: PR33