feat: Allow zones with the same domain name (eg, public and private) (#55)

examples/complete/main.tf

@@ -21,7 +21,9 @@ module "zones" {
     }
 
     "private-vpc.terraform-aws-modules-example.com" = {
-      comment = "private-vpc.terraform-aws-modules-example.com"
+      # in case than private and public zones with the same domain name
+      domain_name = "terraform-aws-modules-example.com"
+      comment     = "private-vpc.terraform-aws-modules-example.com"
       vpc = [
         {
           vpc_id = module.vpc.vpc_id

modules/zones/main.tf

 resource "aws_route53_zone" "this" {
   for_each = var.create ? var.zones : tomap({})
 
-  name          = each.key
+  name          = lookup(each.value, "domain_name", each.key)
   comment       = lookup(each.value, "comment", null)
   force_destroy = lookup(each.value, "force_destroy", false)