Add event gold pickups

data/scenarios/013_wuchao_raid.json

@@ -271,6 +271,7 @@
           ]
         },
         { "type": "log", "text": "Usable Wuchao stores are seized before the granaries burn." },
+        { "type": "grant_gold", "amount": 200, "text": "Wuchao's captured pay chest yields 200 gold." },
         {
           "type": "grant_items",
           "items": [