Add link to WebSocket test if WebSocket connection failed

app/assets/javascripts/editor/editor.js.erb

@@ -620,7 +620,8 @@ configureEditors: function () {
       return;
     }
     $.flash.danger({
-      text: $('#flash').data('message-failure')
+      text: $('#flash').data('websocket-failure'),
+      showPermanent: true
     });
     Sentry.captureException(JSON.stringify(error));
   },

app/assets/stylesheets/base.css.scss

@@ -77,6 +77,11 @@ span.caret {
 
 .flash {
   font-size: 100%;
+
+  a, a:hover {
+    color: white;
+    font-weight: bold;
+  }
 }
 
 .markdown {

app/views/application/_flash.html.slim

@@ -1,5 +1,5 @@
 #flash-container.container
-  #flash.container.fixed_error_messages data-message-failure=t('shared.message_failure')
+  #flash.container.fixed_error_messages data-message-failure=t('shared.message_failure') data-websocket-failure=t('shared.websocket_failure')
     - %w[alert danger info notice success warning].each do |severity|
       div.alert.flash class="alert-#{{'alert' => 'warning', 'notice' => 'success'}.fetch(severity, severity)} alert-dismissible fade show"
         p.mb-0 id="flash-#{severity}" = flash[severity]