docs: fix missing import and logo URL in Migrate from Next.js (#5718)

Author: morinokami

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

@@ -188,6 +188,8 @@ Instead of `page.tsx`, create an `index.tsx` file for the `/` route.
 - `src/app/page.tsx` to `src/app/index.tsx`
 
 ```tsx
++ import { createFileRoute } from '@tanstack/react-router' // [!code ++]
+
 - export default function Home() { // [!code --]
 + export const Route = createFileRoute('/')({ // [!code ++]
 +   component: Home, // [!code ++]
@@ -198,7 +200,7 @@ Instead of `page.tsx`, create an `index.tsx` file for the `/` route.
     <main className="min-h-dvh w-screen flex items-center justify-center flex-col gap-y-4 p-4">
       <img
         className="max-w-sm w-full"
-        src="https://raw.githubusercontent.com/tanstack/tanstack.com/main/src/images/splash-dark.png"
+        src="https://raw.githubusercontent.com/TanStack/tanstack.com/main/public/images/logos/splash-dark.png"
         alt="TanStack Logo"
       />
       <h1>