Update library.properties

library.properties

@@ -3,7 +3,7 @@ version=1.4
 author=Michael Margolis
 maintainer=Paul Stoffregen
 sentence=Timekeeping functionality for Arduino
-paragraph=Date and Time functions, with provisions to synchronize to external time sources like GPS and NTP (Internet).
+paragraph=Date and Time functions, with provisions to synchronize to external time sources like GPS and NTP (Internet).  This library is often used together with TimeAlarms and DS1307RTC.
 category=Timing
 url=http://playground.arduino.cc/code/time
 architectures=*