The UI example for a template is deprecated

[alexec]

When I attempt to submit a workflow template, it uses this YAML:

{
  "metadata": {
    "generateName": "job-",
    "namespace": "argo"
  },
  "spec": {
    "entrypoint": "main",
    "templates": [
      {
        "name": "main",
        "templateRef": {
          "name": "job",
          "template": "main"
        }
      }
    ]
  }
}

But this YAML has a warning in the conditions:

 SpecWarning: Referencing/calling other templates directly on a "template" is deprecated; they should be referenced in a "steps" or a "dag" template. See more: https://github.com/argoproj/argo/blob/master/docs/workflow-templates.md#referencing-other-workflowtemplates

We should probably use YAML that is not deprecated!

@simster7 - would you like to own this?