Add link to paper

This PR ensures people can find the dataset at https://huggingface.co/papers/2407.04621.

README.md

@@ -4,6 +4,9 @@ task_categories:
 language:
 - en
 ---
+
+This dataset is presented in [OneRestore: A Universal Restoration Framework for Composite Degradation](https://huggingface.co/papers/2407.04621).
+
 Preparing the train and test datasets as follows:
 
 ```