add shared link qr code

app/controllers/templates_share_link_qr_controller.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+class TemplatesShareLinkQrController < ApplicationController
+  load_and_authorize_resource :template
+
+  def show
+    return render :disabled, layout: 'plain' unless @template.shared_link?
+
+    shared_link_url = start_form_url(slug: @template.slug, host: form_link_host)
+
+    @qr_svg_code = RQRCode::QRCode.new(shared_link_url, level: :m).as_svg(viewbox: true)
+
+    @page_size =
+      if TimeUtils.timezone_abbr(current_account.timezone, Time.current.beginning_of_year).in?(TimeUtils::US_TIMEZONES)
+        'Letter'
+      else
+        'A4'
+      end
+
+    render :show, layout: false
+  end
+end