OpenNebula/one#7958: Fixed errors in OneKS guides (#818)

This PR includes some fixes to the OneKS documentation prompted by some
errors noticed by a user.

Author: mattrowe-opennebula

content/platform_services/oneks/getting_started/basic_configuration.md

@@ -19,7 +19,25 @@ Verify that the OneKS service is running. On the command line of your OpenNebula
 sudo systemctl status opennebula-ks.service
 ```
 
-The service should be in the active (`running`) state.
+The service should be in the active (`running`) state. 
+
+  * If the service is inactive, start it:
+
+    ```shell
+    sudo systemctl start opennebula-ks.service
+    ```
+
+  * If the service is in a failed state, try restarting it:
+
+    ```shell
+    sudo systemctl restart opennebula-ks.service
+    ```
+
+  * If the service is not found, you may need to install the OneKS package:
+
+    ```shell
+    sudo apt install -y opennebula-ks
+    ```
 
 ## OneGate Service
 
@@ -172,7 +190,7 @@ The generated image is used by the Seed VM to start the K8s Cluster deployment p
 The appliance name and ID can be configured from the control-plane spec configuration file:
 
 ```default
-/var/lib/one/oneks/controlplane/general/controlplane.conf
+/var/lib/one/oneks/controlplanes/general/controlplane.conf
 ```
 
 You can also configure the datastore where the appliance image will be stored. This datastore must be accessible by the OpenNebula Hosts where the K8s Cluster VMs will be deployed.

content/platform_services/oneks/management/customizing_specs.md

@@ -14,8 +14,8 @@ OpenNebula Elastic Kubernetes Service (OneKS) defines Kubernetes deployment prof
 Profiles are used by both control-plane and node-group profiles. By default, the OneKS profile configuration files are located in the following paths:
 
 ```default
-/var/lib/one/oneks/controlplane/general/controlplane.conf
-/var/lib/one/oneks/nodegroup/general/nodegroup.conf
+/var/lib/one/oneks/controlplanes/general/controlplane.conf
+/var/lib/one/oneks/nodegroups/general/nodegroup.conf
 ```
 
 After changing a profile configuration, restart the OneKS service so the updated profile definition is loaded. For service commands, see [Service Management]({{% relref "platform_services/oneks/management/configuration/#service-management" %}}).