How can I disable the auto alphabetical sorting of members in the generated docs?

[vabatta]

pub struct Model {
  pub id: String,
  pub created_at: String
}

should generate

...
    "properties": {
          "id": {
            "$ref": "#/components/schemas/FeedId",
            "description": "The feed's ID.\n\nThis is a unique identifier for the feed. It is\ngenerated automatically when the feed is created."
          },
          "created_at": {
            "type": "string",
            "format": "date-time",
            "description": "The feed's creation timestamp.\n\nThis is the timestamp when the feed was created. It is\ngenerated automatically when the feed is created."
          },
     }
...