docs: add prepare script to generate sidebar (#11894)

www/apps/api-reference/package.json

@@ -10,7 +10,8 @@
     "build:prod": "NEXT_PUBLIC_ENV=production next build",
     "start": "next start",
     "start:monorepo": "yarn start -p 3000",
-    "lint": "next lint --fix"
+    "lint": "next lint --fix",
+    "prep": "node ./scripts/prepare.mjs"
   },
   "dependencies": {
     "@mdx-js/loader": "^3.1.0",
@@ -31,7 +32,6 @@
     "next": "15.0.4",
     "next-mdx-remote": "5.0.0",
     "openapi-sampler": "^1.3.1",
-    "openapi-types": "^12.1.3",
     "pluralize": "^8.0.0",
     "postcss": "8.4.27",
     "prism-react-renderer": "2.4.0",