Add link to Panda Gym paper

README.md

@@ -65,3 +65,5 @@ OrderedDict([('batch_size', 2048),
              ('tau', 0.05),
              ('normalize', False)])
 ```
+
+Panda Gym environments: [arxiv.org/abs/2106.13687](https://arxiv.org/abs/2106.13687)