Support displaying enums in schema types

[w-daghbaji]

Example of an enum type that is not being displayed as part of the schema types :

{
  "components": {
    "schemas": {
      "Color": {
        "type": "string",
        "description": "The color options available.",
        "enum": ["RED", "GREEN", "BLUE", "YELLOW"]
      }
    }
  }
}