add migration for ammo type table and column

priv/repo/migrations/20230331015554_rename_ammo_type_to_type.exs

@@ -0,0 +1,8 @@
+defmodule Cannery.Repo.Migrations.RenameAmmoTypeToType do
+  use Ecto.Migration
+
+  def change do
+    rename table(:ammo_types), to: table(:types)
+    rename table(:packs), :ammo_type_id, to: :type_id
+  end
+end