Revert #631. Add back manage security group flag (#722)

* Revert #631

* fix README lint

* fix README lint for bool

variables.tf

@@ -204,6 +204,18 @@ variable "wait_for_cluster_cmd" {
   default     = "until curl -k -s $ENDPOINT/healthz >/dev/null; do sleep 4; done"
 }
 
+variable "cluster_create_security_group" {
+  description = "Whether to create a security group for the cluster or attach the cluster to `cluster_security_group_id`."
+  type        = bool
+  default     = true
+}
+
+variable "worker_create_security_group" {
+  description = "Whether to create a security group for the workers or attach the workers to `worker_security_group_id`."
+  type        = bool
+  default     = true
+}
+
 variable "worker_create_initial_lifecycle_hooks" {
   description = "Whether to create initial lifecycle hooks provided in worker groups."
   type        = bool