Update MA0016.md (#736)

docs/Rules/MA0016.md

@@ -9,4 +9,4 @@ public IList<string> Prop { get; set; } // ok
 public void Method(Dictionary<string, string> arg) {} // non-compliant
 ````
 
-The analyzer detects `List<T>`, `HashSet<T>`, `Dictionary<TKey,TValue>`, and `System.Collections.ObjectModel.Collection<T>`. The rules is disabled if the property is decorated with an XML serialization attribute.
+The analyzer detects `List<T>`, `HashSet<T>`, `Dictionary<TKey,TValue>`, and `System.Collections.ObjectModel.Collection<T>`. The rule is disabled if the property is decorated with an XML serialization attribute.