[blocks]: Scroll Observer API

[giulianoo0]

Description

The idea is a simple way to detect when a component is visible by wrapping it between a tag, similar to Bootstrap's Scrollspy implementation

I am willing to do it by myself and send a PR.

The following implementation is done through the IntersectionObserver API
https://github.com/shadcn-ui/ui/assets/169609749/9e841a12-8760-431b-9e80-5f2b14e3605d

Example

No response