Update webgl_decals.html

Fix for #12191

examples/webgl_decals.html

@@ -202,6 +202,7 @@
 					intersection.point.copy( p );
 
 					var n = intersects[ 0 ].face.normal.clone();
+					n.transformDirection( mesh.matrixWorld );
 					n.multiplyScalar( 10 );
 					n.add( intersects[ 0 ].point );