insular-observer (npm): Efficiently use an Observer (i.e. IntersectionObserver) without the ugly observer callback. `insular-observer` gives you a simple, per-target `observe/unobserve` API that uses the same observer instance internally.
Keywords: IntersectionObserver|ResizeObserver|Observer|observe|callback|listener|one|single|element|target|just|only|better|API|simple