Update README.md

RLLib_training/README.md

@@ -64,7 +64,7 @@ python baselines/RLLib_training/train_experiment.py
 This will load the gin config file in the folder `experiment_configs/config_examples`.
 
 To visualize the result of a training, one can load a training checkpoint and use the policy learned.
-This is one in the `render_training_result.py` script. One has to modify the `CHECKPOINT_PATH` at the beginning of this script:
+This is done in the `render_training_result.py` script. One has to modify the `CHECKPOINT_PATH` at the beginning of this script:
 
 ```
 CHECKPOINT_PATH = os.path.join(__file_dirname__, 'experiment_configs', 'config_example', 'ppo_policy_two_obs_with_predictions_n_agents_4_map_size_20q58l5_f7',