docs: Fix layout of screen sequence animation (software-mansion#2303)

## Description

So previously, when there was a production build, screens from screen
sequence in hero were wrongly moving into incorrect div. I've wrapped
whole sequence into an additional div, so to disallow screens from
moving there (somehow it fixes this issue).

## Changes

- Wrapped page with additional divs

## Screenshots / GIFs

### Before

![CleanShot 2024-08-13 at 16 40
24@2x](https://github.com/user-attachments/assets/4dc505df-66e7-40a3-bde9-6d334f384c7e)

### After

![CleanShot 2024-08-13 at 16 39
23@2x](https://github.com/user-attachments/assets/6bee706c-d642-4ef1-9d0f-d70105d711d9)

## Checklist

- [ ] Ensured that CI passes

docs/src/pages/index.js

@@ -14,7 +14,9 @@ import styles from './styles.module.css';
 export default function Home() {
   return (
     <Layout description="Native Navigation primitives for your React Native app.">
-      <LandingBackground />
+      <div>
+        <LandingBackground />
+      </div>
       <div className={styles.container}>
         <HomepageStartScreen />
       </div>