docs: unify Bench2Dex citation

CITATION.bib

@@ -0,0 +1,6 @@
+@article{yang2026bench2dex,
+  title={Bench2Dex: Benchmarking Visuo-Tactile Bimanual Dexterous Manipulation Across Dexterous Hands},
+  author={Yang, Zhenjie and Zhang, Yideng and Zhang, Dongjie and Jiang, Chenyu and Liu, Xianshuai and Li, Yufeng and Ge, Zuhao and Jiao, Xingyu and Zhang, Zheng and He, Kaiyu and others},
+  journal={arXiv preprint arXiv:2609.15726},
+  year={2026}
+}

README.md

@@ -44,3 +44,14 @@ Open PRs against **main** here and in the [GitHub leaderboard repository](https:
 ## 🔒 Privacy and permissions
 
 Replace private absolute paths with relative paths or consistent anonymized identifiers, including nested asset paths and error messages. Redact credentials, personal/confidential information, internal URLs, and restricted content in files, media, links, and PR descriptions. Preserve native fields, metrics, episode counts, seeds, task/channel identity, and randomization/protocol metadata. Confirm publication rights under applicable licenses and data-use terms.
+
+## 📝 Citation
+
+```bibtex
+@article{yang2026bench2dex,
+  title={Bench2Dex: Benchmarking Visuo-Tactile Bimanual Dexterous Manipulation Across Dexterous Hands},
+  author={Yang, Zhenjie and Zhang, Yideng and Zhang, Dongjie and Jiang, Chenyu and Liu, Xianshuai and Li, Yufeng and Ge, Zuhao and Jiao, Xingyu and Zhang, Zheng and He, Kaiyu and others},
+  journal={arXiv preprint arXiv:2609.15726},
+  year={2026}
+}
+```