Delete Gemma_Firewalker_AnimLite directory

Files moved to https://github.com/adafruit/Adafruit_Learning_System_Guides/tree/main/Gemma/Gemma_Firewalker_AnimLite

And guides updated
https://learn.adafruit.com/gemma-led-sneakers/arduino-code-for-gemma-m0
https://learn.adafruit.com/firewalker-led-sneakers/firewalker-code

Author: TheKitty