Add library_name metadata

This PR improves the model card by adding `library_name: transformers` to the metadata. This ensures the model is correctly categorized and discoverable within the Hugging Face ecosystem, particularly for users of the `transformers` library, and enables the "how to use" widget on the model page.

README.md

@@ -1,9 +1,10 @@
 ---
-license: apache-2.0
 language:
 - en
 - zh
+license: apache-2.0
 pipeline_tag: text-generation
+library_name: transformers
 ---
 
 # BlockFFN-Small
@@ -25,4 +26,4 @@ If you find our work useful for your research, please kindly cite our paper as f
       year={2025},
       url={https://arxiv.org/pdf/2507.08771}, 
 }
-```
+```