Add Xiakou pursuit scenario

data/campaign/campaign.json

@@ -138,6 +138,11 @@
       "id": "027_jiangling_chase",
       "title": "Jiangling Chase",
       "path": "res://data/scenarios/027_jiangling_chase.json"
+    },
+    {
+      "id": "028_xiakou_pursuit",
+      "title": "Xiakou Pursuit",
+      "path": "res://data/scenarios/028_xiakou_pursuit.json"
     }
   ]
 }