docs(paginator): change heading level for page event (#5444)

src/material-examples/paginator-configurable/paginator-configurable-example.html

@@ -21,8 +21,8 @@
 </md-paginator>
 
 <div *ngIf="pageEvent">
-  <h2>Page Change Event Properties</h2>
+  <h5>Page Change Event Properties</h5>
   <div>List length: {{pageEvent.length}}</div>
   <div>Page size: {{pageEvent.pageSize}}</div>
   <div>Page index: {{pageEvent.pageIndex}}</div>
-</div>
+</div>