docs: add missing comma (#31362)

docs/3.api/5.kit/11.nitro.md

@@ -81,7 +81,7 @@ export default defineNuxtModule({
     const resolver = createResolver(import.meta.url)
 
     addServerHandler({
-      route: '/robots.txt'
+      route: '/robots.txt',
       handler: resolver.resolve('./runtime/robots.get.ts')
     })
   }