docs(hooks/use-revalidator): update code example (#9992)

Co-authored-by: Matt Brophy <[email protected]>

Author: jacobparis

docs/hooks/use-revalidator.md

@@ -39,17 +39,18 @@ Initiates a revalidation.
 
 ```tsx
 function useLivePageData() {
-  const revalidator = useRevalidator();
-  const interval = useInterval(5000);
+  const revalidator = useRevalidator()
 
-  useEffect(() => {
-    if (revalidator.state === "idle") {
-      revalidator.revalidate();
+  useInterval(() => {
+    if (revalidator.state === 'idle') {
+      revalidator.revalidate()
     }
-  }, [interval, revalidator]);
+  }, 5000)
 }
 ```
 
+See [here](https://overreacted.io/making-setinterval-declarative-with-react-hooks/) for a sample `useInterval` implementation.
+
 ## Notes
 
 While you can render multiple occurrences of `useRevalidator` at the same time, underneath it is a singleton. This means when one `revalidator.revalidate()` is called, all instances go into the `"loading"` state together (or rather, they all update to report the singleton state).