docs: vpe security group ids

Author: vkuma17

ibm_catalog.json

@@ -289,6 +289,7 @@
             },
             {
               "key": "vpe_gateway_security_group_ids",
+              "hidden": true,
               "custom_config": {
                 "grouping": "deployment",
                 "original_grouping": "deployment",

solutions/fully-configurable/variables.tf

@@ -713,6 +713,12 @@ variable "vpe_gateway_service_endpoints" {
 }
 
 variable "vpe_gateway_security_group_ids" {
+
+  # Currently unused — the DA doesn't create any custom security groups.
+  # The default security group (automatically created with the VPC) is attached to the VPE gateway since no other security groups are present.
+  # May be useful in the future when DA supports using an existing VPC with custom security groups.
+
+
   description = "List of security group ids to attach to each endpoint gateway."
   type        = list(string)
   default     = null # Let this default value be null instead of []. Provider issue - https://github.com/IBM-Cloud/terraform-provider-ibm/issues/4546