GM_addElement(parent, tag, attributes) {
    return isString(parent)
      ? webAddElement(null, parent, tag)
      : webAddElement(parent, tag, attributes);
  }
Bypasses site's CSP for inline `style`, `link`, and `script`.
@param {Node} [parent]
@param {string} tag
@param {Object} [attributes]
@returns {HTMLElement} it also has .then() so it should be compatible with TM