add DFRobot_C4001 lib

Author: wxzed

repositories.txt

@@ -2046,6 +2046,7 @@ https://github.com/DFRobot/DFRobot_BMP280
 https://github.com/DFRobot/DFRobot_BMP3XX
 https://github.com/DFRobot/DFRobot_BMX160
 https://github.com/DFRobot/DFRobot_BT401
+https://github.com/DFRobot/DFRobot_C4001
 https://github.com/DFRobot/DFRobot_CCS811
 https://github.com/DFRobot/DFRobot_CH423
 https://github.com/DFRobot/DFRobot_DF1101S