Update repositories.txt (#6265)

Add https://github.com/liquidCS/esp32ARP

Author: liquidCS

repositories.txt

@@ -3856,6 +3856,7 @@ https://github.com/LiquidCGS/FastIMU
 https://github.com/littleBitsman/Asynchrony
 https://github.com/liuyinze/CumulocityHttpDownstream
 https://github.com/liuyinze/CumulocityHttpUpstream
+https://github.com/liquidCS/esp32ARP
 https://github.com/llschall/ardwloop-ino
 https://github.com/llelundberg/EasyWebServer
 https://github.com/lmtreser/Robotec