HTML mixed mode
The HTML mixed mode depends on the XML, JavaScript, and CSS modes.
It takes an optional mode configuration
    option, tags, which can be used to add custom
    behavior for specific tags. When given, it should be an object
    mapping tag names (for example script) to arrays or
    three-element arrays. Those inner arrays indicate [attributeName,
    valueRegexp, modeSpec]
    specifications. For example, you could use ["type", /^foo$/,
    "foo"] to map the attribute type="foo" to
    the foo mode. When the first two fields are null
    ([null, null, "mode"]), the given mode is used for
    any such tag that doesn't match any of the previously given
    attributes. For example:
var myModeSpec = {
  name: "htmlmixed",
  tags: {
    style: [["type", /^text\/(x-)?scss$/, "text/x-scss"],
            [null, null, "css"]],
    custom: [[null, null, "customMode"]]
  }
}
    MIME types defined: text/html
    (redefined, only takes effect if you load this parser after the
    XML parser).
