Resource with 'parameters' key and no syntax "cannot unmarshal !!map into []engine.TemplateKindTemplateParameter"

[krbcmt]

Issue type: Bug

Given a kubernetes resource file that has a top-level key parameters and no syntax definition as a comment nor command-line argument a fatal unmarshal error occurs.

Example resource.yml:

---
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
   name: rook-ceph-delete-bucket
provisioner: ceph.rook.io/bucket
reclaimPolicy: Delete
parameters:
  objectStoreName: ceph-object-store
  objectStoreNamespace: rook-ceph

$ kubetpl render resource.yml
yaml: unmarshal errors:
  line 8: cannot unmarshal !!map into []engine.TemplateKindTemplateParameter

According to the documentation, in the absence of a syntax declaration:

kubetpl assumes that template is a regular resource definition file

But it seems that it's maybe actually trying to render it as template-kind?

A workaround is to add # kubetpl:syntax:$ and, in this case, it renders as expected.