Please be aware that this repository is only a release repository for the Arduino framework. The whole documentation can be found in the corresponding Cross-Framework-Platform library repository.
Wait, there are already so many drivers for WS2811/WS2812 on crates.io? At the beginning I was not aware of that WS2811, WS2812, WS2812B, ..., WS2818 are basically the same. I just did not notice it.