add optional shared link to templates

app/controllers/templates_share_link_controller.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class TemplatesShareLinkController < ApplicationController
+  load_and_authorize_resource :template
+
+  def show; end
+
+  def create
+    authorize!(:update, @template)
+
+    @template.update!(template_params)
+
+    head :ok
+  end
+
+  private
+
+  def template_params
+    params.require(:template).permit(:shared_link)
+  end
+end