feat: add postinstall

Author: xiaoyu2er

package.json

@@ -4,6 +4,7 @@
   "description": "",
   "main": "index.js",
   "scripts": {
+    "postinstall": "pnpm run build:packages",
     "format": "biome format --write .",
     "build:packages": "pnpm --filter @next-i18n/const --filter @next-i18n/utils --filter @next-i18n/translate --filter @next-i18n/crawler build",
     "test": "pnpm -r test",