OSDOCS-8220: Added a new requirement to Terraform

Author: EricPonvelle

rosa_planning/rosa-understanding-terraform.adoc

@@ -19,6 +19,7 @@ include::modules/rosa-sts-terraform-prerequisites.adoc[leveloffset=+1]
 [id="additional-resources_rosa-terraform-prereq"]
 .Additional resources
 
+* See xref:../rosa_planning/rosa-cloud-expert-prereq-checklist.adoc#rosa-cloud-expert-prereq-checklist[Prerequisites checklist for deploying ROSA using STS] for a list of requirements that must be met before you can create ROSA clusters by using STS.
 * See xref:../rosa_architecture/rosa-sts-about-iam-resources.adoc[About IAM resources for ROSA clusters that use STS] for information about the AWS account roles.
 * See xref:../cli_reference/rosa_cli/rosa-get-started-cli.adoc[Getting started with the ROSA CLI] for information about installing the ROSA CLI.
 * See Hashicorp's link:https://developer.hashicorp.com/terraform[Terraform documentation] for a comprehensive guide to Terraform.