Add pipeline tag and library name

This PR improves the model card by adding the `pipeline_tag` and `library_name` to the metadata.

These additions ensure:
- The model is correctly categorized as `image-to-image` pipeline, enhancing its discoverability on the Hub.
- Users are aware that the model is compatible with the `transformers` library, providing a familiar interface for interaction.

README.md

@@ -1,5 +1,7 @@
 ---
 license: apache-2.0
+pipeline_tag: image-to-image
+library_name: transformers
 ---
 
 ## NextStep-1: Toward Autoregressive Image Generation with Continuous Tokens at Scale
@@ -99,4 +101,4 @@ If you find NextStep useful for your research and applications, please consider
   journal={arXiv preprint arXiv:2508.10711},
   year={2025}
 }
-```
+```