adding generator which will include :two_factor_authenticable to devise

lib/generators/two_factor_authentication/two_factor_authentication_generator.rb

@@ -0,0 +1,16 @@
+module TwoFactorAuthenticatable
+  module Generators
+    class TwoFactorAuthenticationGenerator < Rails::Generators::NamedBase
+      namespace "two_factor_authentication"
+
+      desc "Add :two_factor_authenticable directive in the given model. Also generate migration for ActiveRecord"
+
+      hook_for :orm
+
+      def inject_two_factor_authentication_content
+        path = File.join("app", "models", "#{file_path}.rb")
+        inject_into_file(path, "two_factor_authenticatable, :", :after => "devise :") if File.exists?(path)
+      end
+    end
+  end
+end