Update migrate-from-next-js.md (#5533)

Author: HirotoShioi

docs/start/framework/react/migrate-from-next-js.md

@@ -129,7 +129,7 @@ import {
   HeadContent,
   Scripts,
 } from "@tanstack/react-router"
-import "./globals.css"
+import appCss from "./globals.css?url"
 
 - export const metadata: Metadata = { // [!code --]
 -   title: "Create Next App", // [!code --]
@@ -145,6 +145,12 @@ export const Route = createRootRoute({
       },
       { title: "TanStack Start Starter" }
     ],
+    links: [
+      {
+        rel: 'stylesheet',
+        href: appCss,
+      },
+    ],
   }),
   component: RootLayout,
 })