feat: change items dump format

src/dumper/main.cs

@@ -104,8 +104,8 @@ class DumpByDaylight
 
         var itemsSerialized = new
         {
-            Camper = new { Items = camperItems.OrderBy(x => x).ToList() },
+            Campers = camperItems.OrderBy(x => x).ToList(),
-            Slasher = new { Powers = slasherPowers.OrderBy(x => x).ToList() }
+            Slashers = slasherPowers.OrderBy(x => x).ToList()
         };
         File.WriteAllText("items.json", JsonConvert.SerializeObject(itemsSerialized, Formatting.Indented));