Updating Readme

Author: Paolo D'Incau

README.md

@@ -65,6 +65,12 @@ The JSON message is built using `jsx` in the module `gcm.erl` and in the end wil
 
 You can send this message using this sentence:
 
+    8> gcm:push(RegisteredName, RegIds, [{<<"data">>, [
+    8>     {<<"message">>, <<"a message">>}
+    8> ]}, {<<"time_to_live">>,3600}, {<<"collapse_key">>,<<"your_update">>}]).
+
+or simply:
+
     8> gcm:push(RegisteredName, RegIds, [{<<"data">>, [
     8>     {<<"message">>, <<"a message">>}
     8> ]}]).