describe the premium support ticket policy on the support page

www/support/app-support.less

@@ -34,5 +34,9 @@
         color: @cryptpad_color_link;
         text-decoration: underline;
     }
+    // add some whitespace to improve readability a bit
+    br {
+        margin: 5px;
+    }
 }
 

www/support/inner.js

@@ -166,12 +166,29 @@ define([
         return $div;
     };
 
+    Messages.support_premiumPriority = "Premium users help support improvements to CryptPad's usability and benefit from prioritized responses to their support tickets."; // XXX
+    Messages.support_premiumLink = 'View subscription options.'; // XXX
+
     // Create a new tickets
     create['form'] = function () {
         var key = 'form';
         var $div = makeBlock(key, true); // Msg.support_formHint, .support_formTitle, .support_formButton
         Pages.documentationLink($div.find('a')[0], 'https://docs.cryptpad.fr/en/user_guide/index.html');
 
+        var accountsLink = h('a', {
+            href: Pages.accounts.upgradeURL,
+        }, Messages.support_premiumLink,);
+
+        var premium = h("div.alert.alert-info", [
+            Messages.support_premiumPriority,
+            ' ',
+            accountsLink,
+        ]);
+
+        if (Pages.areSubscriptionsAllowed()) {
+            $div.find('.cp-sidebarlayout-description').append(premium);
+        }
+
         var form = APP.support.makeForm();
 
         var id = Util.uid();