Add submission # 6231

#6231

Author: ArduinoBot

registry.txt

@@ -8080,3 +8080,4 @@ https://github.com/microbotsio/CodeCell-MicroLink.git|Contributed|CodeCell Micro
 https://github.com/miniiot/miniiot-arduino.git|Contributed|MiniIot
 https://github.com/fanfanlatulipe26/ESP32_ppm.git|Contributed|ESP32_ppm
 https://github.com/DFRobot/DFRobot_C4001.git|Contributed|DFRobot_C4001
+https://github.com/drmpf/RTC_NTP_replacement.git|Contributed|RTC_NTP_replacement