Hey,   I'm trying to integrate gsap with react and have managed to look at a few examples and get a simple tween working, however I'm struggling to work out how to animate all squares in my example and not just the last item.   I would the same affect to apply to all squares or someway to target each square.   I don't really understand what this does, so if someone could explain? 'ref={ a => {this.name = a }'     I have created a codesandbox.io