Replace Admonition Style (cloudposse/terraform-aws-components#1092)

Co-authored-by: Erik Osterman (CEO @ Cloud Posse) <[email protected]>

Author: milldr

src/README.md

@@ -6,12 +6,10 @@ This utilizes
 to assign accounts to various roles. It is also compatible with the
 [GitHub Actions IAM Role mixin](https://github.com/cloudposse/terraform-aws-components/blob/master/mixins/github-actions-iam-role/README-github-action-iam-role.md).
 
-:::caution
-
-Older versions of our reference architecture have an`eks-iam` component that needs to be updated to provide sufficient
-IAM roles to allow pods to pull from ECR repos
-
-:::
+> [!WARNING]
+>
+> Older versions of our reference architecture have an`eks-iam` component that needs to be updated to provide sufficient
+> IAM roles to allow pods to pull from ECR repos
 
 ## Usage