Demonstrates the ease-of-use of the <virtual-scroller> element to build an almost infinite scroller. It simulates pulling data from the server with an artificial 1s delay. It also intentionally avoids prefetching data to make it clearer what is happening. Prefetching could be done by e.g. specifying a rootMargin for the IntersectionObserver to cause the fetch to start before the place-holder element is visible.