Update Useful-links.html

Removed an outdated link.

docs/manual/introduction/Useful-links.html

@@ -73,14 +73,6 @@
 
 		</ul>
 
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-		<h2>More documentation</h2>
-		<ul>
-			<li>
-				[link:http://ushiroad.com/3j/ Three.js walking map] - a graphical breakdown of the structure of a three.js scene.
-			</li>
-		</ul>
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 		<h2>News and Updates</h2>
 		<ul>
 			<li>