Update README.md

Author: raunak-agarwal

README.md

@@ -20,6 +20,7 @@ All available datasets for Instruction Tuning of Large Language Models
 - CrossFit: https://github.com/INK-USC/CrossFit
 - tasksource: https://arxiv.org/abs/2301.05948
 - ExMix: https://arxiv.org/abs/2111.10952
+- VisualDialog: https://visualdialog.org/