Unknown Annotations

[tim-evans]

This adds formal support for unknown annotations.

Unknown Annotations have a particular way of being created; they stuff their type and attributes into the attributes. This means all data is retained for these annotations, while they appear as a homogenous blob. When rendered, these annotations will get categorized into a single bucket of unknown, so they can be rendered for debugging purposes in a document.

For an example, if we import the following HTML document into AtJSON,

<p>Hello, <em>world</em>!</p>

The document created would be a bunch of Unknown Annotations:

{
  "contentType": "application/vnd.atjson+html",
  "content": "<p>Hello, <em>world</em>!</p>",
  "schema": [],
  "annotations": [{
    "type": "-atjson-unknown",
    "start": 0,
    "end": 29,
    "attributes": {
      "type": "-html-p",
      "attributes": {}
    }
  }, {
    "type": "-atjson-unknown",
    "start": 11,
    "end": 25,
    "attributes": {
      "type": "-html-em",
      "attributes": {}
    }
  }, {
    "type": "-atjson-parse-token",
    "start": 0,
    "end": 4,
    "attributes": {}
  }, {
    "type": "-atjson-parse-token",
    "start": 11,
    "end": 15,
    "attributes": {}
  }, {
    "type": "-atjson-parse-token",
    "start": 20,
    "end": 25,
    "attributes": {}
  }, {
    "type": "-atjson-parse-token",
    "start": 26,
    "end": 30,
    "attributes": {}
  }]
}

[bachbui]

Looks good to me. Nice additions to the @atjson/document tests

[blaine]

Fantastic - Understand :all-the-things: