Request for support for attributes to contain complex data but not resources

[cnolewajka]

As per spec, an attribute, even when not a simple value, doesn't have to be a resource:
http://jsonapi.org/format/#document-resource-object-attributes

I would like to request an extension when an attribute can produce a valid json but not necessarily be a simple value, for instance: (see someNonSimpleAttribute)

{
  "data": {
    "id": "1",
    "type": "articles",
    "attributes": {
      "title": "JSON API paints my bikeshed!",
      "numberDecimal": 3.0,
      "numberInt": 0,
      "boolVal": false,
      "someNonSimpleAttribute": {
        "subAtt1": "text",
        "subAtt1": 5
      }
    },
    "relationships": {...
    },
    "links": {
      "self": "http://localhost:56827/articles/1"
    }
  },
  "links": {
    "self": "http://localhost:56827/articles/1"
  },
  "jsonapi": {
    "version": "1.0"
  }
}