Clarify useEffect caveats (#6910)

Author: rickhanlonii

src/content/reference/react/useEffect.md

@@ -64,7 +64,9 @@ function ChatRoom({ roomId }) {
 
 * If your Effect wasn't caused by an interaction (like a click), React will generally let the browser **paint the updated screen first before running your Effect.** If your Effect is doing something visual (for example, positioning a tooltip), and the delay is noticeable (for example, it flickers), replace `useEffect` with [`useLayoutEffect`.](/reference/react/useLayoutEffect)
 
-* Even if your Effect was caused by an interaction (like a click), **the browser may repaint the screen before processing the state updates inside your Effect.** Usually, that's what you want. However, if you must block the browser from repainting the screen, you need to replace `useEffect` with [`useLayoutEffect`.](/reference/react/useLayoutEffect)
+* If your Effect is caused be an interaction (like a click), **React may run your Effect before the browser paints the updated screen**. This ensures that the result of the Effect can be observed by the event system. Usually, this works as expected. However, if you must defer the work until after paint, such as an `alert()`, you can use `setTimeout`. See [reactwg/react-18/128](https://github.com/reactwg/react-18/discussions/128) for more information.
+
+* Even if your Effect was caused by an interaction (like a click), **React may allow the browser may repaint the screen before processing the state updates inside your Effect.** Usually, this works as expected. However, if you must block the browser from repainting the screen, you need to replace `useEffect` with [`useLayoutEffect`.](/reference/react/useLayoutEffect)
 
 * Effects **only run on the client.** They don't run during server rendering.