added arxiv link to readme

README.md

@@ -120,7 +120,7 @@ Current data resolution (as of Oct 31, 2024):
 - While we try to control for false positives, certain soil types can still lead to false positives
 
 ## Citation
-If you use this dataset, please cite our paper: [Paper citation to be added]
+If you use this dataset, please cite our paper: https://arxiv.org/abs/2411.01411
 
 ## Questions or Issues?
 Please open an issue on our GitHub repository at https://github.com/microsoft/ai4g-flood or contact us at [amitmisra@microsoft.com]