Fix missing function keyword (#6527)

* Update use-server.md

* revert export default

Author: AhmedBaset

src/content/reference/react/use-server.md

@@ -153,7 +153,7 @@ export default async function requestUsername(formData) {
 // UsernameForm.js
 'use client';
 
-import {useFormState} from 'react-dom';
+import { useFormState } from 'react-dom';
 import requestUsername from './requestUsername';
 
 function UsernameForm() {
@@ -208,7 +208,7 @@ function LikeButton() {
 'use server';
 
 let likeCount = 0;
-export default async incrementLike() {
+export default async function incrementLike() {
   likeCount++;
   return likeCount;
 }