docs: add and enhance documentation for gui, setup and usage (#34)

docs/setup.md

@@ -0,0 +1,43 @@
+# Forge setup
+
+The initial setup and maintenance of the forge you can use the `forge.sh` script:
+
+<!-- markdownlint-disable MD013 -->
+
+| Command                | Description                                                 |
+| ---------------------- | ----------------------------------------------------------- |
+| `./forge.sh setup`     | Setup the forge for the first time or update existing setup |
+| `./forge.sh heat-up`   | Start the forge                                             |
+| `./forge.sh cool-down` | Stop the forge                                              |
+
+<!-- markdownlint-enable MD013 -->
+
+## What happens during setup
+
+Just in case you haven't have a look at the [forge.sh](../forge.sh) script. The following
+things happen during the setup:
+
+1. The [pre-requisites](../README.md#pre-requisites) are checked
+
+2. You will be asked for your user credentials
+   This is not to spy on you. We need them to execute the [configure_host.yml](../anvil/ansible/playbooks/configure_host.yml).
+   It will configure the necessary settings so you don't have to do that manually.
+   See step 7.
+
+3. A podman network `ublue-os_forge` is created. All containers from this setup will be
+   attached to it in the next step
+
+4. All containers are built and spun up according to the [forge-pod.yml](../forge-pod.yml)
+   specification.
+
+5. The forge SSH key is added to your `~/.ssh/authorized_keys` file.
+   The root certificate and key are created during container build mentioned in the
+   previous step.
+
+6. The forge root certificate is copied to the [data](index.md#configuration) directory.
+
+7. The [configure_host.yml](../anvil/ansible/playbooks/configure_host.yml) playbook mentioned
+   in step 2 is executed.
+   This will created the necessary host entries in `/etc/hosts`, copy the forge root certificate
+   to `/etc/pki/ca-trust/source/anchors/`, `update-ca-trust` and create the example configuration
+   in the [data](index.md#configuration) directory.