Automatically port System.Xml.Xsl.Runtime.XmlQueryNodeSequence.OnItemsChanged triple slash (#3082)

* Automatically port System.Xml.Xsl.Runtime.XmlQueryNodeSequence.OnItemsChanged triple slash

* Clarify summary

* Update xml/System.Xml.Xsl.Runtime/XmlQueryNodeSequence.xml

Co-Authored-By: Ron Petrusha <[email protected]>

* remove BOM character

Author: carlossanlop

xml/System.Xml.Xsl.Runtime/XmlQueryNodeSequence.xml

@@ -418,7 +418,7 @@
       </ReturnValue>
       <Parameters />
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Called when one or more items in the cache have been added or removed. </summary>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>