🚀 Update Vercel deployment snippet & Nullstack

Author: GuiDevloper

examples/active-class-name/api/nullstack.js

@@ -1,11 +1,11 @@
 {
   "private": true,
   "devDependencies": {
-    "nullstack": "~0.17.5"
+    "nullstack": "0.20.0"
   },
   "scripts": {
     "start": "npx nullstack start",
     "build": "npx nullstack build",
-    "vercel-build": "npm run build"
+    "vercel-build": "npm run build && npx nullstack-adapt-vercel"
   }
 }