Add description and URL to library.properties

Updated library properties to include a description and URL.

Author: leonardocavagnis

library.properties

@@ -2,9 +2,9 @@ name=Arduino_LTR381RGB
 version=1.0.0
 author=Arduino
 maintainer=Arduino <info@arduino.cc>
-sentence=
-paragraph=
+sentence=Library for the Lite-On LTR381RGB color and ambient light sensor.
+paragraph=This library provides an easy-to-use interface to read RGB, IR, and ambient light values from the Lite-On LTR381RGB sensor. It supports calibration, gain and resolution configuration, lux calculation, and conversion to HSV/HSL color spaces.
 category=Sensors
-url=
+url=https://github.com/arduino-libraries/Arduino_LTR381RGB
 architectures=*
 includes=Arduino_LTR381RGB.h