fix(suspensive.org): resolve locale initialization issue (#1311)

# Overview

<!--
    A clear and concise description of what this pr is about.
 -->

I address an issue where undefined locale URLs defaulted to 'en' in
Nextra documentation. I've implemented Nextra's middleware to recognize
locale cookies.


https://github.com/user-attachments/assets/03a068df-feef-47f4-b505-532fb29da329

### [AS-IS]
- Custom middleware redirecting undefined locales to '/en'

### [TO-BE]
- Use Nextra's built-in middleware
- Exclude 'img' directory in matcher configuration
- Prevents unnecessary middleware processing for image files, aligning
with Nextra's example configuration (see [Nextra PR
#3439](https://github.com/shuding/nextra/pull/3439/files#diff-e986406290c383f5b481ce7bc0136f142b96083e0807190d530561eea83bfc70R5-R7)
`icon.svg`)


### Issue

Nextra styles may appear broken in development. See [Issue
#3357](shuding/nextra#3357). Could you please
confirm if you're experiencing this as well?


<img width="1797" alt="스크린샷 2024-10-13 오후 8 26 02"
src="https://github.com/user-attachments/assets/88dd507a-81ab-4312-abce-feea2a714495">




## PR Checklist

- [x] I did below actions if need

1. I read the [Contributing
Guide](https://github.com/toss/suspensive/blob/main/CONTRIBUTING.md)
2. I added documents and tests.

Author: kangju2000

docs/suspensive.org/package.json

@@ -30,8 +30,8 @@
     "d3": "^7.9.0",
     "framer-motion": "^11.11.8",
     "next": "catalog:",
-    "nextra": "^3.0.8",
-    "nextra-theme-docs": "^3.0.8",
+    "nextra": "^3.0.11",
+    "nextra-theme-docs": "^3.0.11",
     "react": "catalog:react18",
     "react-dom": "catalog:react18",
     "remark-sandpack": "^0.0.5",

docs/suspensive.org/src/middleware.ts

@@ -1,27 +1,4 @@
-import { type NextRequest, NextResponse } from 'next/server'
-
-const PUBLIC_FILE = /\.(.*)$/
-
-export function middleware(req: NextRequest) {
-  if (
-    req.nextUrl.pathname.startsWith('/_next') ||
-    req.nextUrl.pathname.includes('/api/') ||
-    PUBLIC_FILE.test(req.nextUrl.pathname)
-  ) {
-    return
-  }
-
-  if (
-    !(
-      req.nextUrl.pathname.startsWith('/en') ||
-      req.nextUrl.pathname.startsWith('/ko')
-    )
-  ) {
-    return NextResponse.redirect(
-      new URL(`/en${req.nextUrl.pathname}${req.nextUrl.search}`, req.url)
-    )
-  }
-}
+export { middleware } from 'nextra/locales'
 
 export const config = {
   matcher: [
@@ -31,7 +8,8 @@ export const config = {
      * - _next/static (static files)
      * - _next/image (image optimization files)
      * - favicon.ico (favicon file)
+     * - img (image files)
      */
-    '/((?!api|_next/static|_next/image|favicon.ico).*)',
+    '/((?!api|_next/static|_next/image|favicon.ico|img).*)',
   ],
 }