update README for atari ROMs import

README.md

@@ -86,3 +86,72 @@ pip install cython==0.29.37
 3. install gym[mujoco]
 `pip install gym[mujoco]`
 
+### Import Atari ROMs
+
+If you encounter the error `Unable to find game "[env_name]"` when running a script for Atari environments, it may be due to the absence of Atari ROMs in the `atari_py` package since version 0.2.7. To resolve this issue, you can manually download the ROMs and add them to Gym's registry.
+
+Follow the steps below to import Atari ROMs:
+
+#### Step 1: Download ROMs and Install Dependencies
+Create a new Jupyter notebook (e.g., at the root directory of this project) and run the following code cell just once. This code block downloads the ROMs and installs the necessary dependencies (`unrar` and `atari_py`):
+
+```python
+import urllib.request
+
+# Download the Atari ROMs
+urllib.request.urlretrieve("http://www.atarimania.com/roms/Roms.rar", "Roms.rar")
+
+# Install dependencies
+!pip install unrar
+!pip install atari_py
+
+# Extract the ROMs
+!unrar x Roms.rar
+
+# Organize and compress ROM folders
+!mkdir rars
+!zip HC\ ROMS.zip HC\ ROMS
+!zip ROMS.zip ROMS
+
+# Clean up extracted folders
+!rm -r HC\ ROMS
+!rm -r ROMS
+
+# Move zipped ROMS to the rars folder
+!mv HC\ ROMS.zip rars
+!mv ROMS.zip rars
+```
+
+#### Step 2: Import ROMs to Atari-Py
+Now, use the following lines within the same notebook to import the ROMs to `atari_py`:
+
+```python
+# Import ROMs to atari_py
+!python -m atari_py.import_roms rars
+
+# Clean up downloaded files and folders
+!rm -r rars
+!rm Roms.rar
+```
+
+#### Step 3: Test the Imported ROMs
+Test the imported ROMs by running the following Python code in your Jupyter notebook:
+
+```python
+import gym
+from atariari.benchmark.wrapper import AtariARIWrapper
+
+# Initialize the environment
+env = AtariARIWrapper(gym.make("MsPacmanNoFrameskip-v4"))
+obs = env.reset()
+
+# Perform a single step in the environment
+obs, reward, done, info = env.step(1)
+
+# Check the information provided by the environment (including labels and scores)
+print(info["labels"])
+```
+
+If everything runs smoothly, you have successfully imported the Atari ROMs and set up your environment.
+
+Reference: [StackOverflow answer](https://stackoverflow.com/a/68143504/38626)