Update hellox3dom.html

public/X3DOMTutorial/hellox3dom.html

@@ -80,7 +80,7 @@
           node </a> associates a geometry node with
         nodes that define that geometry's appearance. The following example draws a blue box.        
 <pre>
-<code class="language-html">
+  <code class="language-html">
   &lt;X3D id="shapedata" width="600px" height="600px" style="float:left"&gt;
     &lt;Scene&gt; 
       &lt;background transparency='0' skyColor='1 0 0'&gt; &lt;/background&gt;