This PR enhances the model card for `CodeGoat24/UnifiedReward-Think-qwen-7b` to reflect its role as the pairwise preference reward model for the [Pref-GRPO: Pairwise Preference Reward-based GRPO for Stable Text-to-Image Reinforcement Learning](https://huggingface.co/papers/2508.20751) paper.
It includes the following improvements:
- Updates the model summary to clarify the model's association with the Pref-GRPO paper.
- Links directly to the Pref-GRPO paper on Hugging Face.
- Updates the project page link to the Pref-GRPO specific page.
- Adds a link to the Pref-GRPO GitHub repository.
- Adds the `pipeline_tag: image-text-to-text` to improve discoverability on the Hub for multimodal evaluation tasks.
- Adds the `library_name: transformers` tag to enable the automated "How to use" code snippet.
- Corrects the "Quick Start" code snippet by adding the missing `import requests`.
- Updates the citation block to reference the Pref-GRPO paper.
Please review and merge this PR if everything l…
