style guide: Use emit keyword when emitting events

Author: cameel

docs/style-guide.rst

@@ -233,7 +233,7 @@ Yes:
         bytes32[] options
     );
 
-    LongAndLotsOfArgs(
+    emit LongAndLotsOfArgs(
         sender,
         recipient,
         publicKey,
@@ -251,7 +251,7 @@ No:
                             uint256 amount,
                             bytes32[] options);
 
-    LongAndLotsOfArgs(sender,
+    emit LongAndLotsOfArgs(sender,
                       recipient,
                       publicKey,
                       amount,