Update docs/queries/byrole.mdx

Co-authored-by: Tim Deschryver <[email protected]>

Author: eps1lon

docs/queries/byrole.mdx

@@ -134,7 +134,8 @@ For example in
 
 you can get the "Login failed" alert by calling
 `getByRole('alert', { busy: false })`. To learn more about the busy state see
-[ARIA `aria-busy`](https://www.w3.org/TR/wai-aria-1.2/#aria-busy).
+[ARIA `aria-busy`](https://www.w3.org/TR/wai-aria-1.2/#aria-busy) and
+[MDN `aria-busy` attribute](https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Attributes/aria-busy).
 
 ### `checked`