fix vercel build for the Vue playground

Author: RobinMalfait

packages/@headlessui-vue/package.json

@@ -21,7 +21,7 @@
   },
   "scripts": {
     "playground": "vite serve examples",
-    "playground:build": "vite build examples",
+    "playground:build": "NODE_ENV=production vite build examples",
     "build": "../../scripts/build.sh",
     "test": "../../scripts/test.sh",
     "lint": "../../scripts/lint.sh"

packages/@headlessui-vue/vite.config.js

@@ -48,7 +48,10 @@ const TailwindUIPlugin = ({
 
 module.exports = {
   alias: {
-    '/@headlessui/vue/': path.resolve(__dirname, './src/index.ts'),
+    [process.env.NODE_ENV === 'production' ? '@headlessui/vue' : '/@headlessui/vue/']: path.resolve(
+      __dirname,
+      './src/index.ts'
+    ),
   },
   configureServer: [TailwindUIPlugin],
 }