add colab center

header.html

@@ -37,7 +37,9 @@
     AltDiffusion has been added to 🧨Diffusers, see the documentation page: <a href="https://huggingface.co/docs/diffusers/main/en/api/pipelines/alt_diffusion">🧨 Pipeline doc</a>         
     </p>
     <p style="margin-bottom: 10px; font-size: 94%">
-    <span>你可以在colab试用我们的模型(You can try our models in the colab)</span>
-    <a href="https://colab.research.google.com/drive/1tBJGvocO4TBKBI22oKHtqyPDgcjqDSgF#scrollTo=QkNJDy4sVRBu"><img src="https://colab.research.google.com/assets/colab-badge.svg" alt="Open In Colab"></a>
-    </p>    
+    你可以在colab试用我们的模型(You can try our models in the colab)
+    </p>
+    <div align="center">
+      <a href="https://colab.research.google.com/drive/1tBJGvocO4TBKBI22oKHtqyPDgcjqDSgF#scrollTo=QkNJDy4sVRBu"><img src="https://colab.research.google.com/assets/colab-badge.svg" alt="Open In Colab"></a>
+    </div>    
   </div>