chore: use br in readme

Author: S1M0N38

README.md

@@ -5,9 +5,10 @@
       <img alt="Discord" src="https://img.shields.io/badge/discord-server?style=for-the-badge&logo=discord&logoColor=%23FFFFFF&color=%235865F2"/>
     </a>
   </p>
-  <div style="margin-bottom: 1rem;">
+  <div>
     <img width="1024" alt="Screenshot: BalatroBench" src="https://github.com/user-attachments/assets/33a52df0-a7f8-4784-a640-0212267ed199" />
   </div>
+  <br>
   <p><em>Benchmark LLMs' strategic performance in Balatro</em></p>
 </div>