message: Fix broken example React.memo -> React.useMemo
diff: @@ -24,7 +24,7 @@ function NestedInput() {
  } = useFormContext();
  // we can use React.memo to prevent re-render except dirty state changed
  - return React.memo(
  + return React.useMemo(
  () => (
  <div>
  <input name="test" ref={register} />
  