[Bug]: Example given in "Handling return values in forms" section for "use-server" docs fails to compile

Summary

The following example is given in Handling return values in forms section for "use server" docs, fails to compile.

// requestUsername.js
'use server';

export default async function requestUsername(formData) {
  const username = formData.get('username');
  // ..
}

// UsernameForm.js
'use client';

import { useActionState } from 'react';
import requestUsername from './requestUsername';

function UsernameForm() {
  const [state, action] = useActionState(requestUsername, null, 'n/a');
  // ..
}

Page

https://react.dev/reference/rsc/use-server#handling-return-values

Details

It fails to compile because, as per the useActionState docs,

useActionState(action, initialState, permalink?)

the "action" (requestUsername in this case) should have previousState as the first argument,
and formData as the second argument.

However, for the above example, the requestUsername action has formData as the first argument,
rather than previousState. Therefore, it fails to compile.

The following is the correct way mentioned in the useActionState docs:

async function increment(previousState, formData) {
  return previousState + 1;
}

function StatefulForm({}) {
  const [state, formAction] = useActionState(increment, 0);
  // ..
}

I can raise a PR for the fix, if it's okay.

從 use-server 頁面上連結的「Handling return values in forms」區段開始，將其中的 useActionState 範例與連結的 useActionState 文件進行比較。更新 requestUsername 範例，使其引數與文件中記載的 action 簽章相符，然後驗證文件範例能夠編譯。