Mid implementation of external ammo sources

src/Dodge/Item/Held.hs

@@ -39,6 +39,7 @@ itemFromHeldType ht = case ht of
     GRAPECANNON i -> grapeCannon i
     MINIGUNX i -> miniGunX i
     VOLLEYGUN i -> volleyGun i
+    MULTIGUN i -> multiGun i
     RIFLE -> rifle
     REPEATER -> repeater
     AUTORIFLE -> autoRifle