add nitro v3 to tanstack-start example

Author: birkskyum

vanilla/with-tanstack-start/package.json

@@ -19,6 +19,7 @@
   "devDependencies": {
     "@tailwindcss/postcss": "^4.1.15",
     "@types/node": "^22.5.4",
+    "nitro": "3.0.1-alpha.1",
     "postcss": "^8.5.1",
     "tailwindcss": "^4.1.15",
     "typescript": "^5.7.2",