Merge pull request #175 from keiyamamo/update_docker_doc

enrich docker documentation

docs/docker.md

@@ -2,9 +2,50 @@
 
 # Installing with Docker
 
-## Prerequisites
+The released Docker image can be found [here](https://github.com/KVSlab/VaSP/pkgs/container/vasp).
+Below we assume that you have [Docker](https://docs.docker.com/get-docker/) installed on your system.
+Ensure Docker is running on your system by executing the following command in your terminal:
+```console
+docker info
+```
+If Docker is running, this command will display detailed information about your Docker setup. If Docker is not running, you may see an error message, indicating that you need to start the Docker service.
+
+## Step 1: Pull the Docker image
+
+You can pull the Docker image for the latest `VaSP` package from its
+official [GitHub container registry](https://github.com/KVSlab/VaSP/pkgs/container/vasp) using the following command:
+
+``` console
+docker pull ghcr.io/kvslab/vasp:latest
+```
+
+You can verify that the image has been successfully added by checking the output of 
+
+```console
+docker image -ls
+```
+which should give you (not exactly the same but something very similar)
+
+```
+ghcr.io/kvslab/vasp   master       856878575721   2 months ago   8.87GB
+```
+
+## Step 2: Run the Docker container
+
+After pulling the Docker image, you can run the container using the following command:
+
+``` console
+docker run -w /home/shared/ -v $PWD:/home/shared/ -it ghcr.io/kvslab/vasp:latest
+```
+The `-w` flag sets the working directory inside a Docker container. The `-v` flag is used to mount a volume. In this case, it mounts the current directory ($PWD—a shell variable that represents the present working directory) on your host machine to the `/home/shared/` directory inside the Docker container. This allows you to share files between your host system and the Docker container. You may adjust `/home/shared` depending on your system and structure of the folders.
+
+## Step 3: Verify the installation
 
-- [Docker](https://docs.docker.com/get-docker/) must be installed on your system.
+You can verify that `VaSP` is installed correctly by running vasp commands, e.g.,
+
+```console
+vasp-generate-mesh --help
+```
 
 ## Building our own docker image