Update paper link in medmcqa dataset card (#4290)

* Update README.md

* Replace paper link to abstract page

Co-authored-by: Albert Villanova del Moral <8515462+albertvillanova@users.noreply.github.com>

Commit from https://github.com/huggingface/datasets/commit/0869a3cc8e7d9691bcc45b9e388c68d14bde6dd4

README.md

@@ -52,7 +52,7 @@ pretty_name: MedMCQA
 
 - **Homepage:** https://medmcqa.github.io
 - **Repository:** https://github.com/medmcqa/medmcqa
-- **Paper:** https://arxiv.org/abs/2203.14371
+- **Paper:** [MedMCQA: A Large-scale Multi-Subject Multi-Choice Dataset for Medical domain Question Answering](https://proceedings.mlr.press/v174/pal22a)
 - **Leaderboard:** https://paperswithcode.com/dataset/medmcqa
 - **Point of Contact:** [Aaditya Ura](mailto:aadityaura@gmail.com)