support externalRef in kro

Signed-off-by: Karol Szwaj <karol.szwaj@gmail.com>

On-behalf-of: @SAP karol.szwaj@sap.com

Author: cnvergence

docs/content/usage/integrations/kro.md

@@ -119,7 +119,7 @@ spec:
       address: string
   resources:
     - id: configmap
-      template:
+      externalRef:
         apiVersion: v1
         kind: ConfigMap
         metadata: