Add submission # 6541

#6541

Author: ArduinoBot

registry.txt

@@ -8279,3 +8279,4 @@ https://github.com/RacoonX65/CalibrationLib.git|Contributed|CalibrationLib
 https://github.com/phuongnamzz/HLK-LD2410S.git|Contributed|HLK-LD2410S
 https://github.com/danel32/Arduino-Library-for-MAX7300.git|Contributed|MAX7300
 https://github.com/SpaceTrekKSC/MakerBox.git|Contributed|SpaceTrek MakerBox
+https://github.com/mirosieber/OPT300x.git|Contributed|OPT300x