### Add 'preview' label to properties.json

Source: https://github.com/actions/starter-workflows/blob/main/README.md

Add a 'labels' array with the 'preview' value to your template's `properties.json` file to hide it from public view. Users can still see it by appending `?preview=true` to the workflow creation URL.

```json
{
    "name": "Node.js",
    "description": "Build and test a Node.js project with npm.",
    "iconName": "nodejs",
    "categories": ["Continuous integration", "JavaScript", "npm", "React", "Angular", "Vue"],
    "labels": ["preview"]
}
```

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