Fix mismatch info

I should have sent pull request together, but I discovered this later.

same as previous, `light` should be child of `camera` not `scene`.

threejs/threejs-multiple-scenes-copy-canvas.html

@@ -80,7 +80,7 @@ function main() {
       const intensity = 1;
       const light = new THREE.DirectionalLight(color, intensity);
       light.position.set(-1, 2, 4);
-      scene.add(light);
+      camera.add(light);
     }
 
     return {scene, camera, controls};