Update ubuntu.md

Using the repository to install docker

Author: leongkio

content/manuals/engine/install/ubuntu.md

@@ -130,6 +130,11 @@ Docker from the repository.
      $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \
      sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
    sudo apt-get update
+
+   sudo apt install apt-transport-https ca-certificates curl software-properties-common
+   curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
+   sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu `lsb_release -cs` test"
+   sudo apt-get update
    ```
 
    > [!NOTE]