chore: import upstream snapshot with attribution

rllib/examples/_old_api_stack/algorithms/cartpole-bc.yaml

@@ -0,0 +1,26 @@
+# @OldAPIStack
+# To generate training data, first run:
+# $ ./train.py --run=PPO --env=CartPole-v1 \
+#      --stop='{"timesteps_total": 50000}' \
+#      --config='{"output": "dataset", "output_config": {"format": "json", "path": "/tmp/out", "max_num_samples_per_file": 1}, "batch_mode": "complete_episodes"}'
+cartpole-bc:
+    env: CartPole-v1
+    run: BC
+    stop:
+        timesteps_total: 500000
+    config:
+        # Works for both torch and tf.
+        framework: torch
+        enable_rl_module_and_learner: false
+        enable_env_runner_and_connector_v2: false
+        # In order to evaluate on an actual environment, use these following
+        # settings:
+        evaluation_num_env_runners: 1
+        evaluation_interval: 1
+        evaluation_config:
+            input: sampler
+        # The historic (offline) data file from the PPO run (at the top).
+        input: dataset
+        input_config:
+            format: json
+            paths: /tmp/out