Add serve:build script

Author: hasparus

package.json

@@ -6,6 +6,7 @@
   "packageManager": "[email protected]",
   "scripts": {
     "build": "next build && next-image-export-optimizer",
+    "serve:build": "pnpx serve out",
     "check:links": "lychee --verbose --no-progress './src/pages/**/*.mdx' --base https://graphql.org",
     "dev": "next",
     "format": "pnpm format:check --write",
@@ -15,7 +16,6 @@
     "lint:docs:ci": "eslint --ignore-path .gitignore src/pages/learn --format eslint-formatter-github",
     "postbuild": "next-sitemap",
     "prebuild": "tsx src/get-github-info.ts",
-    "start": "next start",
     "test": "echo \"no tests\" && exit 1",
     "validate:snippets": "node scripts/validate-snippets.js"
   },