Lightweight tween scroll animations

There should be a lightweight tween animation component that responds to scroll events. An example of the data configuration from a well-known site:

```
data-anim-tween="{"relativeTo":".section-cameras .hero-container", "start":"15rh", "end":"30rh", "opacity":[1, 0.35], "disabledWhen": ["no-sticky","reduced-motion"]}"
```