Add paper abstract and link to Github repository

This PR adds the paper abstract and a link to the Github repository, improving the information available on the model card.

README.md

@@ -1,17 +1,18 @@
 ---
-license: mit
 language:
 - en
+library_name: transformers
+license: mit
 pipeline_tag: image-to-image
 tags:
 - multimodal
-library_name: transformers
 ---
 
 ## 🔥🔥🔥 News!!
 * Apr 25, 2025: 👋 We release the inference code and model weights of Step1X-Edit. [inference code](https://github.com/stepfun-ai/Step1X-Edit)
 * Apr 25, 2025: 🎉 We have made our technical report available as open source. [Read](https://arxiv.org/abs/2504.17761)
 
+
 <!-- ## Image Edit Demos -->
 
 <div align="center">