Update dictionary.md

Author: corranrogue9

graph/patterns/dictionary.md

@@ -45,7 +45,7 @@ The following example demonstrates defining a dictionary that can contain string
   <ComplexType Name="Dictionary" OpenType="true">
     <Annotation Term="Core.Description" String="A dictionary of name-value pairs. Names must be valid property names, values may be restricted to a list of types via an annotation with term `Validation.OpenPropertyTypeConstraint`." />
   </ComplexType>
-  <ComplexType Name="stringDictionary" BaseType="WorkloadNamespace.Dictionary"> //// TODO does this need to be marked as an open type?
+  <ComplexType Name="stringDictionary" OpenType="true" BaseType="WorkloadNamespace.Dictionary">
     <Annotation Term="Org.OData.Validation.V1.OpenPropertyTypeConstraint">
       <Collection>
         <String>Edm.String</String>