jsonschemaを生成するprmdで「Meta is empty,..」と出る

prmdを使っているのですが、
bundle exec prmd init --yaml website > docs/schema/schemata/yml/website.yml
で生成したwebsite.ymlを以下のように変更しました。

yaml
1---
2"$schema": http://json-schema.org/draft-04/hyper-schema
3title: Website
4description: WebSite Data API
5stability: prototype
6strictProperties: true
7type:
8- object
9definitions:
10  id:
11    description: unique identifier of website
12    example: 1
13    readOnly: true
14    #format: uuid
15    type:
16    - integer #string
17  title:
18    description: unique title of website
19    example: "exampleのサイト"
20    readOnly: true
21    type:
22    - string
23  url: 
24    description: unique url of website
25    example: "https://example.com/"
26    readOnly: true
27    type:
28    - string
29  description: 
30    description: unique description of website
31    example: "このサイトはexampleが作ったサイトです"
32    readOnly: true
33    type:
34    - string
35  created_at:
36    description: when website was created
37    format: date-time
38    type:
39    - string
40  updated_at:
41    description: when website was updated
42    format: date-time
43    type:
44    - string
45links:
46- description: Create a new website data.
47  href: "/websites"
48  method: POST
49  rel: create
50  schema:
51    properties: {}
52    type:
53    - object
54  title: Create
55- description: Delete an existing website.
56  href: "/websites/{(%2Fschemata%2Fwebsite%23%2Fdefinitions%2Fidentity)}"
57  method: DELETE
58  rel: destroy
59  title: Delete
60- description: Info for existing website.
61  href: "/websites/{(%2Fschemata%2Fwebsite%23%2Fdefinitions%2Fidentity)}"
62  method: GET
63  rel: self
64  title: Info
65- description: List existing websites.
66  href: "/websites"
67  method: GET
68  rel: instances
69  title: List
70- description: Update an existing website.
71  href: "/websites/{(%2Fschemata%2Fwebsite%23%2Fdefinitions%2Fidentity)}"
72  method: PATCH
73  rel: update
74  schema:
75    properties: {}
76    type:
77    - object
78  title: Update
79properties:
80  created_at:
81    "$ref": "/schemata/website#/definitions/created_at"
82  id:
83    "$ref": "/schemata/website#/definitions/id"
84  titie:
85    "$ref": "/schemata/website#/definitions/title"
86  url:
87    "$ref": "/schemata/website#/definitions/url"
88  description:
89    "$ref": "/schemata/website#/definitions/description"
90  updated_at:
91    "$ref": "/schemata/website#/definitions/updated_at"
92id: schemata/website
93