Update Enumerable.xml

Author: gewarren

xml/System.Linq/Enumerable.xml

@@ -416,7 +416,7 @@
 
 ## Remarks
 
-This method is comparable to the <xref:System.Linq.Enumerable.GroupBy%2A> methods where each grouping is being aggregated into a single value as opposed to allocating a collection for each group.
+This method is comparable to the <xref:System.Linq.Enumerable.GroupBy``2(System.Collections.Generic.IEnumerable{``0},System.Func{``0,``1})> methods where each grouping is aggregated into a single value as opposed to allocating a collection for each group.
 
 ## Examples