Allow configurable addition to the order confirmation message

src/pretix/control/forms/event.py

@@ -435,6 +435,7 @@ class EventSettingsForm(SettingsForm):
         'checkout_email_helptext',
         'presale_has_ended_text',
         'voucher_explanation_text',
+        'checkout_success_text',
         'show_dates_on_frontpage',
         'show_date_to',
         'show_times',

src/pretix/control/templates/pretixcontrol/event/settings.html

@@ -188,6 +188,7 @@
                     </div>
                 </div>
 
+                {% bootstrap_field sform.checkout_success_text layout="control" %}
                 {% bootstrap_field sform.checkout_email_helptext layout="control" %}
                 {% bootstrap_field sform.checkout_phone_helptext layout="control" %}
                 {% bootstrap_field sform.banner_text layout="control" %}