Update repositories.txt

Author: KITTEN2008

repositories.txt

@@ -2,6 +2,7 @@ https://github.com/jobitjoseph/WitAITTS
 https://github.com/hackffm/Single_WS2812_Bitbang_Write
 https://github.com/MrYsLab/Telemetrix4RpiPico2w
 https://github.com/sstaub/Seesaw
+https://github.com/KITTEN2008/SN74HC573
 https://github.com/DavidSAlexander/STM32RomWebFlasher
 https://github.com/seeimadeit/AES128ESP32
 https://github.com/BojanJurca/Thread-safe-ping-Arduino-library-for-ESP32