Add pipeline tag, paper link, and code link to model card

This PR improves the model card for the AIGIBench model by:
- Adding the `pipeline_tag: image-classification` to ensure discoverability on the Hugging Face Hub.
- Including a direct link to the paper: [Is Artificial Intelligence Generated Image Detection a Solved Problem?](https://huggingface.co/papers/2505.12335).
- Adding a link to the official GitHub repository: https://github.com/HorizonTEL/AIGIBench.

These additions will make the model more accessible and provide clearer context for users.

README.md

@@ -1,8 +1,10 @@
 ---
-license: cc-by-nc-sa-4.0
 datasets:
 - HorizonTEL/AIGIBench
+license: cc-by-nc-sa-4.0
+pipeline_tag: image-classification
 ---
+
 <div align="center">
  <br>
 <h1>Is Artificial Intelligence Generated Image Detection a Solved Problem?</h1>
@@ -17,6 +19,14 @@ datasets:
 </div>
 
 <sup>1</sup>Nanjing University of Information Science and Technology <sup>2</sup>University of Siena
+<p align="center">
+  <a href='https://huggingface.co/papers/2505.12335'>
+    <img src='https://img.shields.io/badge/Paper-HuggingFace-yellow?style=flat&logo=Hugging%20Face&logoColor=yellow'>
+  </a>
+  <a href='https://github.com/HorizonTEL/AIGIBench'>
+    <img src='https://img.shields.io/badge/Code-GitHub-181717?style=flat&logo=github'>
+  </a>
+</p>
 </div>