Add missing metadata and improve model card

This PR adds the missing `pipeline_tag`, `library_name`, and `license` metadata to the model card. It also clarifies the model's purpose.

README.md

@@ -1,6 +1,9 @@
-This model was fine-tuned on Qwen to generate reflection in the test-time scaling framework introduced
-in [From Reflection to Perfection: Scaling Inference-Time Optimization for Text-to-Image Diffusion
-Models via Reflection Tuning](https://huggingface.co/papers/2504.16080).
+---
+pipeline_tag: text-to-image
+library_name: transformers
+license: mit
+---
 
-To know more about the details and how it should be used, please check out the paper and the
-[code repository](https://github.com/Diffusion-CoT/ReflectionFlow).
+This model was fine-tuned on Qwen to generate reflections in the test-time scaling framework introduced in [From Reflection to Perfection: Scaling Inference-Time Optimization for Text-to-Image Diffusion Models via Reflection Tuning](https://huggingface.co/papers/2504.16080). This model enhances text-to-image generation by incorporating reflection tuning.
+
+For more details and usage instructions, please refer to the paper and the [code repository](https://github.com/Diffusion-CoT/ReflectionFlow). The project page can be found [here](https://diffusion-cot.github.io/reflection2perfection).