fix search nextra

docs/package.json

@@ -2,6 +2,7 @@
   "scripts": {
     "dev": "next dev",
     "build": "next build",
+    "postbuild": "pagefind --site .next/server/app --output-path public/_pagefind",
     "start": "next start"
   },
   "license": "MIT",
@@ -15,6 +16,7 @@
     "react-dom": "^18.2.0"
   },
   "devDependencies": {
+    "pagefind": "^1.3.0",
     "typescript": "^5.9.3"
   }
 }