Update repositories.txt (#5722)

Add rotaryDecoder8, an Arduino library for a PCF8575 based rotary decoder - supports 8 rotary encoders.

Author: RobTillaart

repositories.txt

@@ -5525,6 +5525,7 @@ https://github.com/RobTillaart/RAIN
 https://github.com/RobTillaart/randomHelpers
 https://github.com/RobTillaart/relativity
 https://github.com/RobTillaart/rotaryDecoder
+https://github.com/RobTillaart/rotaryDecoder8
 https://github.com/RobTillaart/rotaryDecoderSwitch
 https://github.com/RobTillaart/RS485
 https://github.com/RobTillaart/RunAvgWeight