Fix link to email of point of contact (#3)

- Fix link to email of point of contact (5d511621ebbf423255047d641afe30d98727b6e9)

README.md

@@ -104,7 +104,7 @@ dataset_info:
 - **Repository:** https://github.com/google-research-datasets/ToTTo
 - **Paper:** https://arxiv.org/abs/2004.14373
 - **Leaderboard:** https://github.com/google-research-datasets/ToTTo#leaderboard
-- **Point of Contact:** [email](totto@google.com)
+- **Point of Contact:** [totto@google.com](mailto:totto@google.com)
 
 ### Dataset Summary