This PR improves the dataset card for PMR-Bench by adding:
- A link to the paper: [Medical Triage as Pairwise Ranking: A Benchmark for Urgency in Patient Portal Messages](https://huggingface.co/papers/2601.13178).
- A link to the project page.
- Relevant metadata including the `text-classification` task category and language tags.
- A descriptive summary of the dataset and its intended use case for medical triage.
- A BibTeX citation for the paper.