Add Vercel adapter and update package dependencies

astro.config.mjs

@@ -4,6 +4,8 @@ import react from '@astrojs/react';
 
 import tailwind from '@astrojs/tailwind';
 
+import vercel from '@astrojs/vercel/serverless';
+
 // https://astro.build/config
 export default defineConfig({
   integrations: [
@@ -12,4 +14,7 @@ export default defineConfig({
       applyBaseStyles: false,
     }),
   ],
-});
+
+  output: 'server',
+  adapter: vercel(),
+});