message: update example 01 docker
diff: @@ -79,21 +79,16 @@ docker container prune
  ```bash
  docker image rm <IMAGE ID>
  +docker rmi <IMAGE ID>
  docker image prune
  ```
  > `prune`: Remove all dangling images, that is, all images with name equals <none>. Dangling images are not referenced by other images and are safe to delete
  -- Let's run again the docker image:
  -
  -```bash
  -docker images
  -docker run hello-world
  -```
  -
  -- Finally, we can run a container as interactive mode:
  +- Let's try another image, ubuntu. We can run a container as interactive mode:
  ```bash
  docker run ubuntu // exited automatically
  +docker ps -a
  docker run -it ubuntu sh
  ```
  