Add submission # 5266

#5266

Author: ArduinoBot

registry.txt

@@ -7520,3 +7520,4 @@ https://github.com/ncmreynolds/milesTag.git|Contributed|milesTag
 https://github.com/nhjschulz/cfsm.git|Contributed|CFSM
 https://github.com/bitcode-tech/uart_keyboard.git|Contributed|UART_Keyboard
 https://github.com/julio22011/EasyOledUI.git|Contributed|EasyOledUI
+https://github.com/DefHam140/ZModbusRTU.git|Contributed|ZModbusRTU