Fix the description of the SK6812 LED in the example code.

The SK6812 expects the data for the green LED first, then red and
finally blue. It should be described as a GRB LED.

docs/modules/ws2812.md

@@ -53,7 +53,7 @@ ws2812.write({pin =  4, data = string.char(255, 0, 0, 255, 0, 0)},
 ```
 
 ```lua
-ws2812.write({pin = 8, reset = 800, t0h = 3, t0l = 9, t1h = 6, t1l = 6, data = string.char(1, 0, 0)}) -- turn the SK6812 RGB led on the ESP32-C3-DevKitM-1 to green
+ws2812.write({pin = 8, reset = 800, t0h = 3, t0l = 9, t1h = 6, t1l = 6, data = string.char(1, 0, 0)}) -- turn the SK6812 GRB led on the ESP32-C3-DevKitM-1 to green
 ```
 
 # Buffer module