Update `README.md`

The compose file will create the `slurm_cluster` network for all containers and will assign the

following IPv4 static addresses:

* slurmctld: 192.18.0.129

* c1: 192.18.0.10

* c2: 192.18.0.11

* c3: 192.18.0.12

* c4: 192.18.0.13

* login: 192.18.0.128

* `slurmctld`: 192.18.0.129

* `c1`: 192.18.0.10

* `c2`: 192.18.0.11

* `c3`: 192.18.0.12

* `c4`: 192.18.0.13

* `login`: 192.18.0.128

## Package contents

- `slurm-docker-cluster-node/Dockerfile`: dockerfile with specific software for

  the compute nodes. Specific for scord. NEEDS TO BE BUILT BEFORE RUNNING THE

  CLUSTER.

- `refresh.sh`: script for refreshing the scord installation in the cluster.

- `scripts/register_cluster.sh`: script for registering the cluster with the `slurmdbd` daemon.

- `scripts/refresh.sh`: script for refreshing the scord installation in the cluster.

  This script uses the `slurm-docker-cluster-node` image to generate the

  binaries so that there are no compatibility issues with dependencies.

42 directories, 149 files

```

## Optional configurations

### Cluster registration

Though it's not required for the cluster to work properly, the newly created

cluster can be registered with the internal `slurmdbd` daemon. To do so, run the

`scripts/register_cluster.sh` script:

```console

scripts/register_cluster.sh

```

### Enabling name resolution

Though the cluster internally will be able to properly resolve the names of each service,

the host will be unable to do so. The simplest solution is to edit the `/etc/hosts` file

and add entries for the services which have static IPv4 addresses assigned:

```

192.18.0.128	login

192.18.0.129	slurmctld

192.18.0.10	c1

192.18.0.11	c2

192.18.0.12	c3

192.18.0.13	c4

```

## Usage

1. Find out the UID and GID of the host user that will be shared with the

       --build-arg SHARED_GROUP_NAME=example-user \

       --build-arg=SHARED_GROUP_GID=1000

   ```

3. Run the cluster with `docker compose up -d`.

3. Start the cluster with `docker compose up -d`.

4. You can log into the cluster containers as root with

   `docker compose exec <container> bash`.

5. Alternatively, if ssh keys for the shared user have been configured in the `user_home` volume and the host's