convert to pnpm workspace

packages/playground/package.json

@@ -0,0 +1,18 @@
+{
+  "name": "playground",
+  "private": true,
+  "scripts": {
+    "build": "nuxt build",
+    "dev": "nuxt dev",
+    "generate": "nuxt generate",
+    "preview": "nuxt preview",
+    "prepare": "nuxt prepare"
+  },
+  "dependencies": {
+    "trpc-nuxt": "link:../trpc",
+    "zod": "^3.16.0"
+  },
+  "devDependencies": {
+    "nuxt": "3.0.0-rc.3"
+  }
+}