feat: 添加21点游戏

handler/blackjack/controller/response.go

@@ -0,0 +1,13 @@
+package controller
+
+type BackJackResponse struct {
+	Code int
+	Description string
+}
+
+func NewBlackJackResponse(code int, description string) *BackJackResponse {
+	return &BackJackResponse{
+		Code: code,
+		Description: description,
+	}
+}