title: Animating scrollTop using react-spring
body: <p>this should be simple but i think i'm missing something crucial on how Spring works, the documentation is not much of help.</p>
  
  <p>I have a dynamic list, the user can add elements, when that happens i want to use React Spring to animate the scroll to the bottom of the page (identified by <code>currentBottomY</code> variable)</p>
  
  <p>i have something like this</p>
  
  <pre><code>const mainRef = useRef&lt;HTMLElement | null&gt;(null)
  
  const [y, setY] = useSpring({
      from: { y: mainRef?.current?.scrollTop || 0 },
      onFrame: props =&gt; {
         mainRef.current.scrollTop = props.y
      },
  })
  
  const onAddRow = () =&gt; {
      setY({ y: currentBottomY })
  }
  
  return (
      &lt;animated.div ref={mainRef}&gt;
          &lt;List /&gt;
      &lt;/animated.div&gt;
  )
  </code></pre>
  
  <p>I'm getting errors saying i cannot define <code>from</code> and <code>onFrame</code> in there but in the docs it says otherwise, i really cannot make heads or tails on this, any help?</p>