Update repositories.txt (arduino#3154)

Author: nthnn

repositories.txt

@@ -22,6 +22,7 @@ https://github.com/addy123d/I2CDisplayController
 https://github.com/ZakKemble/LM73
 https://github.com/felias-fogg/avrCalibrate
 https://github.com/crunchysteve/EdgieD
+https://github.com/nthnn/TCS3200
 https://github.com/nthnn/Anomalia
 https://github.com/nthnn/Navigador
 https://github.com/nthnn/PH4502C-Sensor