Update library.properties

Author: facchinm

library.properties

@@ -5,7 +5,7 @@ maintainer=Daniele Aimo ([email protected])
 sentence=Library used to connect OPTA and OPTA Expansion Modules on I2C / UART 
 paragraph=This library discover the presence of different Expansions (for example OPTA Digital) present on the I2C bus, automatically assing addresses to them and allow to control their Input/Output from the Opta Controller.
 category=Communication
-url=
+url=https://github.com/arduino-libraries/Arduino_Opta_Blueprint
 architectures=*
 includes=OptaBlue.h
 depends=Arduino_SerialUpdater, Arduino_DebugUtils