Add new paper citation to Oceananigans section (#4899)

* Add new paper citation to Oceananigans section

* Clean up blank lines in index.md

Removed unnecessary blank lines in the papers section.

Author: navidcy

docs/src/index.md

@@ -102,6 +102,8 @@ the features they describe! Also, if you have developed a new feature in Oceanan
 
 If you have work using Oceananigans that you would like to have listed here, please open a pull request to add it or let us know!
 
+1. Zhang, Y., Kang, W., and Marshall, J. (2025) [How does ice shell geometry shape ocean dynamics on icy moons?](https://doi.org/10.48550/arXiv.2510.25988), _arXiv preprint_, arXiv:2510.25988. DOI: [10.48550/arXiv.2510.25988](https://doi.org/10.48550/arXiv.2510.25988)
+
 1. Shikanian, A. and Parfenyev, V. (2025) [The effects of no-slip boundaries and external force torque on two-dimensional turbulence in a square domain](https://doi.org/10.48550/arXiv.2508.13590), _arXiv preprint_, arXiv:2508.13590. DOI: [10.48550/arXiv.2508.13590](https://doi.org/10.48550/arXiv.2508.13590)
 
 1. Souza, A. N., Silvestri, S., Deck, K., Bischoff, T., Ferrari, R., and Flierl, G. R. (2025) [Surface to seafloor: A generative AI framework for decoding the ocean interior state](https://doi.org/10.48550/arXiv.2504.15308), _arXiv preprint_, arXiv:2504.15308. DOI: [10.48550/arXiv.2503.12845](https://doi.org/10.48550/arXiv.2504.15308)