Add submission # 6708

#6708

Author: ArduinoBot

registry.txt

@@ -8233,3 +8233,4 @@ https://github.com/Nezaemmy/Neza74HC165.git|Contributed|Neza74HC165
 https://github.com/AmissDrake/MDLib.git|Contributed|MDLib
 https://github.com/chrissank/JKBMSInterface.git|Contributed|JKBMSInterface
 https://github.com/adafruit/Adafruit_MLX90632.git|Recommended|Adafruit MLX90632 Library
+https://github.com/GyverLibs/uButton.git|Contributed|uButton