Draft-06 schema should match latest GitHub source

[ssilverman]

I just noticed that the downloadable Draft-06 schema (https://json-schema.org/draft-06/schema from https://json-schema.org/specification-links.html#draft-6) doesn't match what's on GitHub: https://github.com/json-schema-org/json-schema-spec/blob/draft-06/schema.json

This is different:

        "patternProperties": {
            "type": "object",
            "additionalProperties": { "$ref": "#" },
            "propertyNames": { "format": "regex" },
            "default": {}
        },

"propertyNames": { "format": "regex" }, is missing.

[Relequestual]

I'm not sure this change was correct in the first place.
json-schema-org/json-schema-spec#704 (comment)

[handrews]

format is open-ended so there are no invalid values. Unknown value effectively serve as documentation.