update notifications

notifications.rst

@@ -66,7 +66,7 @@ Once the alerter parameters are configured, as described above, the next step is
 
 Navigate to the :ref:`administration` -> Configuration screen. Next, locate the ``soc -> config -> server -> modules -> elastalertengine`` settings.
 
-In the **Additional Alerters** configuration setting, add the name of each alerter that should be activated, one alerter name per line. 
+In the **Additional Alerters** configuration setting, add the name of each alerter that should be activated, one alerter name per line. For example, to add both slack and email: 
 
 ::