Note repeatable items Helm limitation

Author: ajp-io

docs/reference/custom-resource-config.mdx

@@ -746,6 +746,7 @@ Repeatable items do not use the `default` or `value` fields, but instead a `valu
 
 * Repeatable items work only for text, textarea, and file types.
 * Repeatable item names must only consist of lower case alphanumeric characters.
+* Repeatable items are only supported for Kubernetes manifests, not Helm charts.
 
 ### Template Targets