Inventory: add concrete use-case examples

inventory/src/machines/machines.cue

@@ -1,20 +1,8 @@
 package machines
 
-#ServiceRole: "server" | "client" | "both"
 
 #machine: machines: [string]: {
     name: string,
     description?: string,
-    icon?: string,
-    // each machines service
-    services?: [string]: {
-        // Roles if specificed must contain one or more roles
-        // If no roles are specified, the service module defines the default roles.
-        roles?: [ ...#ServiceRole ],
-        // The service config to use
-        // This config is scoped to the service.module, only serializable data (strings,numbers, etc) can be assigned here
-        config: {
-            ...
-        }
-    }
+    icon?: string
 }