Add task categories and link to GREx paper

Hi! I'm Niels from the community science team at Hugging Face. I've updated the dataset card for gRefCOCO to improve its discoverability and documentation.

This PR:
- Adds relevant `task_categories` to the metadata: `image-segmentation`, `object-detection`, and `image-to-text`.
- Updates the header to include a link to the consolidated paper: [GREx: Generalized Referring Expression Segmentation, Comprehension, and Generation](https://huggingface.co/papers/2601.05244).
- Maintains the existing usage examples for training and inference based on MDETR.

This should help users find the dataset when filtering by task and provide them with the necessary context from the latest paper.

README.md

@@ -1,14 +1,23 @@
-# gRefCOCO - Dataset for [CVPR2023 Highlight] GRES: Generalized Referring Expression Segmentation
+---
+task_categories:
+- image-segmentation
+- object-detection
+- image-to-text
+---
+
+# gRefCOCO - Dataset for Generalized Referring Expression Segmentation, Comprehension, and Generation (GREx)
+
 [![PyTorch](https://img.shields.io/badge/PyTorch-1.11.0-%23EE4C2C.svg?style=&logo=PyTorch&logoColor=white)](https://pytorch.org/)
 [![Python](https://img.shields.io/badge/Python-3.7%20|%203.8%20|%203.9-blue.svg?style=&logo=python&logoColor=ffdd54)](https://www.python.org/downloads/)
 [![PWC](https://img.shields.io/endpoint.svg?url=https://paperswithcode.com/badge/gres-generalized-referring-expression-1/generalized-referring-expression-segmentation)](https://paperswithcode.com/sota/generalized-referring-expression-segmentation?p=gres-generalized-referring-expression-1)
 
-**[🏠[Project page]](https://henghuiding.github.io/GRES/)**   **[📄[GRES Arxiv]](https://arxiv.org/abs/2306.00968)**   **[📄[GREC Arxiv]](https://arxiv.org/abs/2308.16182)**
+**[🏠[Project page]](https://henghuiding.github.io/GRES/)**   **[📄[Paper (GREx)]](https://huggingface.co/papers/2601.05244)**   **[📄[GRES Arxiv]](https://arxiv.org/abs/2306.00968)**   **[📄[GREC Arxiv]](https://arxiv.org/abs/2308.16182)**
+
+This repository contains information and tools for the **gRefCOCO** dataset, proposed in the paper:
+> [GREx: Generalized Referring Expression Segmentation, Comprehension, and Generation](https://huggingface.co/papers/2601.05244)  
+> Chang Liu, Henghui Ding, Xudong Jiang
 
-This repository contains information and tools for the [gRefCOCO](https://henghuiding.github.io/GRES/) dataset, proposed by the **CVPR2023 Highlight** paper:
-> [GRES: Generalized Referring Expression Segmentation](https://arxiv.org/abs/2306.00968)  
-> Chang Liu, Henghui Ding, Xudong Jiang  
-> CVPR 2023 Highlight, Acceptance Rate 2.5%
+gRefCOCO is the first large-scale GREx dataset that contains multi-target, no-target, and single-target expressions and their corresponding images with labeled targets. It is designed to be backward-compatible with classic Referring Expression (REx) tasks.
 
 <div align="center">
   <img src="https://github.com/henghuiding/ReLA/blob/main/imgs/fig1.png?raw=true" width="100%" height="100%"/>
@@ -54,9 +63,15 @@ Our project is built upon [refer](https://github.com/lichengunc/refer) and [coco
 
 
 ## BibTeX
-Please consider to cite GRES/GREC if it helps your research.
+Please consider to cite GRES/GREC/GREx if it helps your research.
 
 ```bibtex
+@article{GREx,
+  title={{GREx}: Generalized Referring Expression Segmentation, Comprehension, and Generation},
+  author={Liu, Chang and Ding, Henghui and Jiang, Xudong},
+  journal={arXiv preprint arXiv:2601.05244},
+  year={2026}
+}
 @inproceedings{GRES,
   title={{GRES}: Generalized Referring Expression Segmentation},
   author={Liu, Chang and Ding, Henghui and Jiang, Xudong},
@@ -69,22 +84,4 @@ Please consider to cite GRES/GREC if it helps your research.
   journal={arXiv preprint arXiv:2308.16182},
   year={2023}
 }
-```
-We also recommend other highly related works:
-```bibtex
-@article{VLT,
-  title={{VLT}: Vision-language transformer and query generation for referring segmentation},
-  author={Ding, Henghui and Liu, Chang and Wang, Suchen and Jiang, Xudong},
-  journal={IEEE Transactions on Pattern Analysis and Machine Intelligence},
-  year={2023},
-  volume={45},
-  number={6},
-  publisher={IEEE}
-}
-@inproceedings{MeViS,
-  title={{MeViS}: A Large-scale Benchmark for Video Segmentation with Motion Expressions},
-  author={Ding, Henghui and Liu, Chang and He, Shuting and Jiang, Xudong and Loy, Chen Change},
-  booktitle={ICCV},
-  year={2023}
-}
-```
+```