add subproject kontor-rails

kontor-rails/db/migrate/20250626095807_create_volumes.rb

@@ -0,0 +1,12 @@
+class CreateVolumes < ActiveRecord::Migration[8.0]
+  def change
+    create_table :volumes do |t|
+      t.datetime :created_date
+      t.datetime :last_modified_date
+      t.integer :version
+      t.string :name
+      t.belongs_to :comic
+    end
+    change_column :volumes, :id, :string
+  end
+end