3 worlds from AWS Robotics

[ClassLongJoe1112]

Summary

• 3 worlds: small warehouse, small house and the first floor of a hospital, are extracted from AWS Robotics team.
• 3 2D maps (in .yaml) is created using the tb3_simulation_launch.py from nav2_bringup package, which has already included a builtin navigating algorithm and a turtlebot3 (waffle) is used. To produce a map file for the desired world, try:

  
  # Make sure you have installed the nav2_bringup package
  export TURTLEBOT3_MODEL=waffle
  export GAZEBO_MODEL_PATH=$GAZEBO_MODEL_PATH:/opt/ros/humble/share/turtlebot3_gazebo/models
  export GAZEBO_MODEL_PATH=$GAZEBO_MODEL_PATH:<models_file_for_the_desired_world>
  ros2 launch nav2_bringup tb3_simulation_launch.py headless:=False world:=<world_file> slam:=True

To save the map you are happy with, try:

ros2 run nav2_map_server map_saver_cli -f

Please visit map_ws/src/README.md for more information

### Issues
From the [AWS Robotics team](https://github.com/aws-robotics), there are 5 worlds: small warehouse, small house, hospital, racetrack and bookstore.
- For [**small warehouse**](https://github.com/aws-robotics/aws-robomaker-small-warehouse-world) and [**hospital**](https://github.com/aws-robotics/aws-robomaker-hospital-world), there is no issue opening them directly with command `gazebo <world_file>` or using them as the launch argument for `tb3_simulation_launch.py` launch file to change its world.
- For [**small house**](https://github.com/aws-robotics/aws-robomaker-small-house-world), there is no issue opening it directly, but it failed to open as a launch argument for `tb3_simulation_launch.py` (which crash my virtual machine). Compare small house with small warehouse and hospital, I observed there are several high resolution photos inside the house as decorations, and also there are relatively more light sources. After removing a few of them, I successfully open it in `tb3_simulation_launch.py`. (Because of this, the `aws_house.world` file I saved in the repository is a reduced version.)
- More weird issues occur in [**racetrack**](https://github.com/aws-robotics/aws-robomaker-racetrack-world) and [**bookstore**](https://github.com/aws-robotics/aws-robomaker-bookstore-world): 
    1. If we want to open it directly using `gazebo <world_file>`, it will only be opened successfully if the current directory of your bash is in `aws-robomaker-racetrack-world` (the name of the original [**racetrack**](https://github.com/aws-robotics/aws-robomaker-racetrack-world) repository). 
    > Which refer to the command below:
    > ```bash
    > $ cd aws-robomaker-racetrack-world
    > $ gazebo worlds/racetrack_day.world
    > ```
    > Otherwise, the world will be completely empty even though the models are loaded into gazebo.

    2. Similar to **small house**, both of the world files cannot be opened as a launch argument for `tb3_simulation_launch.py`.

In conclustion, I mainly think the above issues are caused by the relatively low specification for my virtual machine, since reducing high resolution photos and light sources in **small house** actually helps. It is still need to be solved in the future researches.

[ClassLongJoe1112]

I resolved the issues according to @j3soon's suggestions. In addition, I adjusted the mounting path ("workspaceMount") of the docker container in .devcontainer/devcontainer.json, just like​ the template_ws written by @j3soon and @YuZhong-Chen.