docs: cite original paper

README.md

@@ -26,6 +26,8 @@ dataset, _ = dgl.load_graphs("./data/processed/chameleon.bin")
 
 Thank you [@severo](https://huggingface.co/severo) for helping me [figure out the usage](https://discuss.huggingface.co/t/can-i-use-a-pickle-file-with-the-data-files-argument-with-datasets/72189/2?u=sauravmaheshkar).
 
+Pre-processed as per the official codebase of https://arxiv.org/abs/2210.02016
+
 ## Citations
 
 ```