Improve network documentation

Signed-off-by: Marc Schöchlin <[email protected]>

docs/guides/deploy-guide/services/network.md

@@ -5,27 +5,28 @@ sidebar_position: 15
 
 # Network
 
+Two options are available for installing the Openstack network.
+
+* Open Virtual Network with Open vSwitch:
+  * the default, recommended
+  * configuration value `ovn`
+* Open vSwitch:
+  * configuration value `openvswitch`
+
+The selected option is configured in the following file:
+```yaml title="environments/kolla/configuration.yml"
+# neutron
+neutron_plugin_agent: "ovn"
+```
+
 1. Open vSwitch (OVS)
 
    ```
    osism apply -a pull openvswitch
    osism apply openvswitch
    ```
 
-2. Open Virtual Network (OVN)
-
-   In `environments/kolla/configuration.yml` the parameter `neutron_plugin_agent` is set to
-   `ovn` if OVN is used as a network plugin. The parameter is set to `ovn` by default in the
-   Cookiecutter.
-
-   ```yaml title="environments/kolla/configuration.yml"
-   # neutron
-   neutron_plugin_agent: "ovn"
-   ```
-
-   Otherwise the network plugin is set to `openvswitch`.
-   If the `neutron_plugin_agent` is set to `openvswitch`, this step does not need to be done.
-
+2. Optional: Open Virtual Network (OVN)
    Before the deployment of OVN, the deployment of Open vSwitch must already have been done.
 
    ```