Add library name tag to model card

This PR adds the `library_name: transformers` tag to the model card. This ensures the "How to use" section is displayed correctly on the Hugging Face model page, providing users with readily available code examples.

README.md

@@ -1,6 +1,7 @@
 ---
 license: mit
 pipeline_tag: video-text-to-text
+library_name: transformers
 ---
 
 # Vamba