Add JSONID characterisation format

[ross-spencer]

At some point this should be done. Maybe once there has been an opportunity to collab more and determine best fit. Making sure there is clear documentation about mandatory fields is probably good practice here as well.

The user-agent field is probably a good field to output. But there should be others.

{
  "content_length": 4339,
  "number_of_lines": 147,
  "line_warning": false,
  "top_level_keys_count": 17,
  "top_level_keys": [
    "access",
    "created",
    "custom_fields",
    "expires_at",
    "files",
    "id",
    "is_draft",
    "is_published",
    "links",
    "media_files",
    "metadata",
    "parent",
    "pids",
    "revision_id",
    "status",
    "updated",
    "versions"
  ],
  "top_level_types": [
    "map",
    "string",
    "map",
    "string",
    "map",
    "string",
    "bool",
    "bool",
    "map",
    "map",
    "map",
    "map",
    "map",
    "integer",
    "string",
    "string",
    "map"
  ],
  "depth": 6,
  "heterogeneous_list_types": false,
  "fingerprint": {
    "unf": "UNF:6:ZHgVHqjWQl21unuzn/+UXQ==",
    "cid": "bafkreiawyfmgaa7uscmtbbsgtu5lrd2ewpesihhm634sy6tbet3ywdnlae"
  },
  "doctype": "JSON",
  "encoding": "UTF-8",
  "agent": "jsonid/0.0.0 (ffdev-info)"
}