增加查询游戏折扣详情方法

src/promote/PromoteDiscountServiceInterface.php

@@ -19,4 +19,13 @@ interface PromoteDiscountServiceInterface
      * @return array
      */
     public function childDiscountList($parent_id, array $child_games = []): array;
+
+    /**
+     * 查询游戏折扣详情
+     * @param $game_id
+     * @param $child_id
+     * @param $promote_id
+     * @return array
+     */
+    public function gameDiscountInfo($game_id, $child_id, $promote_id): array;
 }