Modified ROS2UnityComponent recommended use

Author: adamdbrw

README.md

@@ -48,9 +48,10 @@ Please see OS-specific instructions:
 3. Go to Assets in the menu bar (at the top of the Unity Window).
 4. Select `Import Package` → `Custom Package`.
 5. In the file browser, select the .unitypackage file built by `create_unity_asset` script (by default located in `install/unity_package`) and follow the instructions on the screen.
-6. In the project tab, navigate to `Assets/Ros2ForUnity/Scripts`, select any object in the hierarchy tab, and add a script component by dragging `ROS2TalkerExample.cs` to the inspector tab. ROS2UnityComponent dependency will be added automatically (see the screenshot below).
-7. Select another object in the hierarchy tab and add repeat the previous step using `ROS2ListenerExample.cs`.
-8. Once you start the project in Unity, you should be able to see two nodes talking with each other in  Unity Editor's console or use `ros2 node list` and `ros2 topic echo /chatter` to verify ros2 communication.
+6. Create a top-level object containing ROS2UnityComponent.cs. This is the central Monobehavior for ROS2ForUnity that manages all the nodes. Refer to class documentation for details.
+7. Add example script to any object in the hierarchy tab, e.g. by dragging `ROS2TalkerExample.cs` to the object in the inspector tab.
+8. Select another object in the hierarchy tab and add repeat the previous step using `ROS2ListenerExample.cs`.
+9. Once you start the project in Unity, you should be able to see two nodes talking with each other in  Unity Editor's console or use `ros2 node list` and `ros2 topic echo /chatter` to verify ros2 communication.
 
 ![usage.png](usage.png)