update path in examples

Author: looeee

examples/webgl_gpu_particle_system.html

@@ -17,7 +17,7 @@
 		<script src="./js/controls/TrackballControls.js"></script>
 		<script src="./js/libs/dat.gui.min.js"></script>
 		<script src="./js/libs/stats.min.js"></script>
-		<script src="./js/GPUParticleSystem.js"></script>
+		<script src="./js/objects/GPUParticleSystem.js"></script>
 
 		<script>
 			var camera, tick = 0,