Update index.html

Remove link to three.js dev tools browser extension.

index.html

@@ -60,7 +60,6 @@
 					<ul>
 						<li><a href="https://github.com/mrdoob/three.js/">github</a></li>
 						<li><a href="https://github.com/mrdoob/three.js/archive/master.zip">download</a></li>
-						<li><a href="https://chrome.google.com/webstore/detail/threejs-developer-tools/ebpnegggocnnhleeicgljbedjkganaek">devtools</a></li>
 					</ul>
 
 					<h2>Resources</h2>