微信小程序模板参数类型-最多20个汉字

https://developers.weixin.qq.com/miniprogram/dev/api-backend/open-api/subscribe-message/subscribeMessage.send.html#%E8%AE%A2%E9%98%85%E6%B6%88%E6%81%AF%E5%8F%82%E6%95%B0%E5%80%BC%E5%86%85%E5%AE%B9%E9%99%90%E5%88%B6%E8%AF%B4%E6%98%8E