Add pipeline tag and improve metadata

This PR adds the `pipeline_tag: image-segmentation` to the model metadata to improve discoverability. It also updates the paper link to point to the Hugging Face paper page.

README.md

@@ -1,14 +1,15 @@
 ---
-license: mit
 datasets:
 - mcosarinsky/CheXmask-U
+license: mit
+pipeline_tag: image-segmentation
 tags:
 - medical
 ---
 
 # CheXmask-U: Uncertainty-aware landmark-based anatomical segmentation for chest X-rays
 
-📄 [Paper](https://arxiv.org/abs/2512.10715) | 💻 [Code](https://github.com/mcosarinsky/CheXmask-U) | 🎛️ [Interactive Demo](https://huggingface.co/spaces/mcosarinsky/CheXmask-U) | 📦 [Dataset](https://huggingface.co/datasets/mcosarinsky/CheXmask-U)
+📄 [Paper](https://huggingface.co/papers/2512.10715) | 💻 [Code](https://github.com/mcosarinsky/CheXmask-U) | 🎛️ [Interactive Demo](https://huggingface.co/spaces/mcosarinsky/CheXmask-U) | 📦 [Dataset](https://huggingface.co/datasets/mcosarinsky/CheXmask-U)
 
 ---