Update Libraries-and-Plugins.html

docs/manual/en/introduction/Libraries-and-Plugins.html

@@ -52,6 +52,7 @@
 			<li>[link:https://github.com/gkjohnson/urdf-loaders/tree/master/javascript urdf-loader]</li>
 			<li>[link:https://github.com/NASA-AMMOS/3DTilesRendererJS 3d-tiles-renderer-js]</li>
 			<li>[link:https://github.com/kaisalmen/WWOBJLoader WebWorker OBJLoader]</li>
+			<li>[link:https://github.com/agviegas/IFC.js IFC.js]</li>
 		</ul>
 
 		<h3>3D Text and Layout</h3>
@@ -66,6 +67,14 @@
 		<ul>
 			<li>[link:https://github.com/creativelifeform/three-nebula three-nebula]</li>
 		</ul>
+		
+		
+		<h3>Inverse Kinematics</h3>
+
+		<ul>
+			<li>[link:https://github.com/jsantell/THREE.IK THREE.IK]</li>
+			<li>[link:https://github.com/lo-th/fullik fullik]</li>
+		</ul>
 
 		<h3>Game AI</h3>