Update README.md

Remove mathematical delimiter

README.md

@@ -52,7 +52,7 @@ This dataset contains trajectories generated by a [PPO](https://arxiv.org/abs/17
 
 ## Dataset Structure
 ### Data Instances
-Each data instance represents a single step consisting of tuples of the form (observation, action, reward, done, truncated) = $(o_t, a_t, r_{t+1}, done_{t+1}, trunc_{t+1})$.
+Each data instance represents a single step consisting of tuples of the form (observation, action, reward, done, truncated) = (o_t, a_t, r_{t+1}, done_{t+1}, trunc_{t+1}).
 
 ```json
 {'action': 1,