Add avr-fast-shift (#5054)

adbancroft · web-flow · commit a558f8f649ef · 2024-09-02T23:13:20.000Z
diff --git a/repositories.txt b/repositories.txt
@@ -7303,3 +7303,4 @@ https://github.com/CMB27/ModbusRTUComm
 https://github.com/Zhentao-Lin/ESP32_WS2812_Lib
 https://github.com/stack-chan/stackchan-arduino
 https://github.com/adbancroft/avr-fast-div
+https://github.com/adbancroft/avr-fast-shift
