Nested definitions is not supported

[sankoshine]

Take a look at following schema:

{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "title": "Example Schema",
    "description": "This schema is awesome.",
    "type": "object",
    "properties": {
        "lower": {
            "description": "Lower clothing.",
            "oneOf": [
                { "$ref": "#/definitions/pants/ccc" },
                { "$ref": "#/definitions/shorts/ddd" }
            ]
        }
    },
    "definitions": {
        "pants": {
            "ccc": { "description": "Long on the legs.", "type": "string" }
        },
        "shorts": {
            "ddd": { "description": "Short on the legs.", "type": "string" }
        }
    }
}

And the output:

# Example Schema

This schema is awesome.

The schema defines the following properties:

## `lower`

Lower clothing.

The object must be one of the following types:

* `undefined`
* `undefined`

---

# Sub Schemas

The schema defines the following additional types:

## `pants` (undefined)

## `shorts` (undefined)