Added ui-grid-auto-scroll third party plugin

Author: stevezau

misc/tutorial/299_third_party_features.ngdoc

@@ -16,3 +16,6 @@ Draggable rows in UI Grid.
 Allows querying for odata v3/v4 services
 <br>https://github.com/mirik123/ui-grid-odata
 
+### **ui-grid-auto-scroll** ###
+Auto scrolls when new added added to ui-grid
+<br>https://github.com/stevezau/ui-grid-auto-scroll