automatically create constructor jsdoc in template

[zavr-1]

const { _Cookies, connect, express, _Keygrip } = require('./cookies')

/**
 * The interface for Cookies: signed and unsigned cookies based on Keygrip.
 * @type {new (req: !http.IncomingMessage, res: !http.ServerResponse, opts: !_goa.CookiesOptions) => Cookies}
 */
const $Cookies = _Cookies

/**
 * Signing and verifying data (such as cookies or URLs) through a rotating credential system.
 * @type {new (keys: !Array<string>, algorithm?: string, encoding?: string) => Keygrip}
 */
const $Keygrip = _Keygrip