Simple RL notebook (#1395)

* Simple RL notebook

* Add link to the notebook

Co-authored-by: Young <[email protected]>

Author: lihuoran

docs/component/rl/framework.rst

@@ -42,4 +42,8 @@ As you may have noticed, a training vessel itself holds all the required compone
 
 With a training vessel, the trainer could finally launch the training pipeline by simple, Scikit-learn-like interfaces (i.e., ``trainer.fit()``).
 
-The API for Trainer and TrainingVessel and can be found `here <../../reference/api.html#module-qlib.rl.trainer>`__.
+The API for Trainer and TrainingVessel and can be found `here <../../reference/api.html#module-qlib.rl.trainer>`__.
+
+The RL module is designed in a loosely-coupled way. Currently, RL examples are integrated with concrete business logic.
+But the core part of RL is much simpler than what you see.
+To demonstrate the simple core of RL, `a dedicated notebook <https://github.com/microsoft/qlib/tree/main/examples/rl/simple_example.ipynb>`__ for RL without business loss is created.

examples/rl/README.md

@@ -53,3 +53,8 @@ python -m qlib.rl.contrib.backtest --config_path ./experiment_config/backtest/co
 ```
 
 The backtest workflow will use the trained model in `checkpoints/`. The backtest summary can be found in `outputs/`.
+
+## Others
+The RL module is designed in a loosely-coupled way. Currently, RL examples are integrated with concrete business logic.
+But the core part of RL is much simpler than what you see.
+To demonstrate the simple core of RL, [a dedicated notebook](./simple_example.ipynb) for RL without business loss is created.