docs: add arXiv link

README.md

@@ -10,6 +10,6 @@ pinned: true
 
 ## Reconstructing Humans with a Biomechanically Accurate Skeleton
 
-Official Huggingface demo implementation of [HSMR](https://github.com/IsshikiHugh/HSMR).
+Official Huggingface demo implementation of [HSMR](https://arxiv.org/abs/2503.21751).
 
 Please refer to the [GitHub Repo](https://github.com/IsshikiHugh/HSMR) for the code release and more details. This Huggingface space is only for demo purposes.