Moved code into src folder. Added build for component library.

src/components/hooks/useSticky.js

@@ -0,0 +1,25 @@
+import { useState, useEffect, useRef } from 'react';
+
+export function useSticky({ enabled = true, threshold = 1 }) {
+  const [isSticky, setIsSticky] = useState(false);
+  const ref = useRef(null);
+
+  useEffect(() => {
+    let observer;
+    const handler = ([entry]) => setIsSticky(entry.intersectionRatio < threshold);
+
+    if (enabled && ref.current) {
+      observer = new IntersectionObserver(handler, { threshold: [threshold] });
+      observer.observe(ref.current);
+    }
+    return () => {
+      if (observer) {
+        observer.disconnect();
+      }
+    };
+  }, [ref, enabled, threshold]);
+
+  return { ref, isSticky };
+}
+
+export default useSticky;