Add Wu river line scenario

data/campaign/campaign.json

@@ -258,6 +258,11 @@
       "id": "051_eastern_front_alarm",
       "title": "Eastern Front Alarm",
       "path": "res://data/scenarios/051_eastern_front_alarm.json"
+    },
+    {
+      "id": "052_wu_river_line",
+      "title": "Wu River Line",
+      "path": "res://data/scenarios/052_wu_river_line.json"
     }
   ]
 }