Add link to code

This PR adds a link to the Github repository, enabling people to find the codebase more easily.

README.md

@@ -12,6 +12,7 @@ base_model:
 - Efficient-Large-Model/Sana_1600M_4Kpx_BF16
 pipeline_tag: text-to-image
 ---
+
 <p align="center" style="border-radius: 10px">
   <img src="https://raw.githubusercontent.com/NVlabs/Sana/refs/heads/main/asset/logo.png" width="35%" alt="logo"/>
 </p>