chore(server): add note about defining index

CHANGELOG.md

@@ -12,7 +12,7 @@ See updating [Changelog example here](https://keepachangelog.com/en/1.0.0/)
 
 ### Changed
 
-- upcloud_server: When modifying `network_interfaces`, match configured network interfaces to the server's actual network interfaces by `index` and `ip_address` (in addition to list order). This is to avoid public and utility network interfaces being re-assigned when the interfaces are re-ordered or when interface is removed from middle of the list. This might result to inaccurate diffs in the Terraform plan when interfaces are re-ordered or when interface is removed from middle of the list.
+- upcloud_server: When modifying `network_interfaces`, match configured network interfaces to the server's actual network interfaces by `index` and `ip_address` (in addition to list order). This is to avoid public and utility network interfaces being re-assigned when the interfaces are re-ordered or when interface is removed from middle of the list. This might result to inaccurate diffs in the Terraform plan when interfaces are re-ordered or when interface is removed from middle of the list. We recommend explicitly setting the value for `index` in configuration, when interfaces are re-ordered or when interface is removed from middle of the list.
 
 ## [5.14.0] - 2024-10-28
 

internal/service/server/server.go

@@ -176,7 +176,9 @@ func resourceServerV0() *schema.Resource {
 				Type: schema.TypeList,
 				Description: `One or more blocks describing the network interfaces of the server.
 
-    In addition to list order, the configured network interfaces are matched to the server's actual network interfaces by ` + "`" + `index` + "`" + ` and ` + "`" + `ip_address` + "`" + ` fields. This is to avoid public and utility network interfaces being re-assigned when the server is updated. This might result to inaccurate diffs in the plan, when interfaces are re-ordered or when interface is removed from the middle of the list.`,
+    In addition to list order, the configured network interfaces are matched to the server's actual network interfaces by ` + "`" + `index` + "`" + ` and ` + "`" + `ip_address` + "`" + ` fields. This is to avoid public and utility network interfaces being re-assigned when the server is updated. This might result to inaccurate diffs in the plan, when interfaces are re-ordered or when interface is removed from the middle of the list.
+
+    We recommend explicitly setting the value for ` + "`" + `index` + "`" + ` in configuration, when re-ordering interfaces or when removing interface from middle of the list.`,
 				Required: true,
 				MinItems: 1,
 				Elem: &schema.Resource{