Fix typo

Author: Dylan Babbs

interleave-layers/demo.html

@@ -19,7 +19,7 @@ <h1>Interleave vector and object layers</h1>
         <p>Insert an object layer between the two vector layers</p>
     </div>
     <p>This example shows how to interleave an object layer and the vector layer. It is possible to do it dynamically during the map runtime.
-      The map is loaded with the deefault vector layer, after that the layer is split into two and the new object layer is inserted between them.
+      The map is loaded with the default vector layer, after that the layer is split into two and the new object layer is inserted between them.
     </p>
     <div id="map"></div>
     <h3>Code</h3>