Can't find any of the "real application packages" referenced in the top-level README.md file

まだ誰も着手していません。

## Issue template

- Version or commit hash: galactic branch

#### Steps to reproduce the issue
In [README.md](https://github.com/micro-ROS/micro-ROS-demos/tree/galactic#real-application-packages), there is reference to the following packages:
- [rad0_actuator](https://github.com/micro-ROS/micro-ROS-demos/tree/galactic#rad0_actuator)
- [rad0_altitude_sensor](https://github.com/micro-ROS/micro-ROS-demos/tree/galactic#rad0_altitude_sensor)
- [rad0_control](https://github.com/micro-ROS/micro-ROS-demos/tree/galactic#rad0_control)
- [rad0_display](https://github.com/micro-ROS/micro-ROS-demos/tree/galactic#rad0_display)

However, I can't seem to find that code anywhere. Would you mind adding github links to the corresponding source files for those sections?

The only package I see that seems related is the [RAD0_control](https://github.com/micro-ROS/micro-ROS-demos/tree/galactic/rclcpp/RAD0_control) package, but that doesn't have any of the functionality referenced above.

README.md の Real Application Packages セクションを確認し、そこにある rad0_actuator、rad0_altitude_sensor、rad0_control、rad0_display への参照をリポジトリの内容と比較してください。既存の rclcpp/RAD0_control パッケージを確認したうえで、対応するソースの場所へのリンクまたは正しい参照を使ってセクションを更新し、一覧にある各パッケージを見つけられるようにしてください。

索引モデルが issue の本文から書いたものです。