Edit volume of dive knife.

data/json/items/tools.json

@@ -1789,7 +1789,7 @@
     "//": "Too small to be effectively used for butchering, still not bad at it due to serrated edge.",
     "description": "This is a short, sturdy knife with a serrated edge for cutting lines and straps, and a blunt tip for prying.  Used primarily by divers, it is very light and takes up virtually no space in one's pockets.",
     "weight": "226 g",
-    "volume": 0,
+    "volume": "250 ml",
     "price": 14000,
     "cutting": 12,
     "material": [ "steel", "plastic" ],