code: func (w *Webhook) SendTextMsg(content string, isAtAll bool, mobiles ...string) error {
  	return w.SendPayload(&Payload{
  		MsgType: "text",
  		Text: struct {
  			Content string `json:"content"`
  		}{
  			Content: content,
  		},
  		At: struct {
  			AtMobiles []string `json:"atMobiles"`
  			IsAtAll   bool     `json:"isAtAll"`
  		}{
  			AtMobiles: mobiles,
  			IsAtAll:   isAtAll,
  		},
  	})
  }
docs: // SendTextMsg 发送文本消息