Generate does not output placeholders for boolean properties

[willosborne]

Bug Report

Steps to Reproduce:

Add a boolean field to a node, relationship or metadata object

e.g.

{
    "type": "object",
    "properties": {
          "propertyBoolean": {
                  "type": "boolean"
           }
      }
}

Expected Result:

{
     "propertyBoolean": "{{ PROPERTY_BOOLEAN }}"
}

Actual Result:

{}

Environment:

Latest version of CLI

Additional Context:

Placeholder values are tricky here. We can't just output false as this could be dangerous.
We should consider a warning to use enums instead of booleans.
Suggested fix for booleans is:

• output a string placeholder (will fail validation)
• emit a warning saying to use enums instead
• add a spectral rule to also emit this warning on pattern files