feat: json 404 response in api endpoint

pages/api/[...404].ts

@@ -0,0 +1,8 @@
+import { NextApiHandler, NextApiRequest, NextApiResponse } from 'next'
+
+const HelloWorld:NextApiHandler = (_req: NextApiRequest, res: NextApiResponse) =>{
+	res.statusCode = 404
+	res.json({ code: 404, message: '요청하신 URL에 페이지가 존재하지 않습니다.' })
+}
+
+export default HelloWorld