feat: add lunar lander config

stoix/configs/env/envpool/lunarlander.yaml

@@ -0,0 +1,16 @@
+# ---Environment Configs---
+env_name: envpool # Used for logging purposes and selection of the corresponding wrapper.
+
+scenario:
+  name: LunarLander-v2
+  task_name: lunarlander # For logging purposes.
+
+kwargs: {}
+
+# Defines the metric that will be used to evaluate the performance of the agent.
+# This metric is returned at the end of an experiment and can be used for hyperparameter tuning.
+eval_metric: episode_return
+
+# optional - defines the threshold that needs to be reached in order to consider the environment solved.
+# if present then solve rate will be logged.
+solved_return_threshold: 200.0