core&ui: add training maintainer

packages/ui-default/locales/zh.yaml

@@ -893,6 +893,7 @@ Total Score: 总分数
 Total Time (Seconds): 总耗时 (秒)
 Total Time: 总耗时
 Total: 总计
+Training Maintainer: 训练管理员
 Training requirement is not satisfied.: 不满足训练条件。
 training_create: 创建训练
 training_edit: 编辑训练

packages/ui-default/templates/training_edit.html

@@ -26,6 +26,13 @@
               <p class="help-text">{{ _('Introduce must not exceed 500 characters and it will be shown in the list view.') }}</p>
             </label>
           </div></div>
+          {{ form.form_text({
+            columns:12,
+            label:'Training Maintainer',
+            name:'maintainer',
+            help_text:_('Allow to maintain this {0}').format(_('training')),
+            value:tdoc.maintainer|default('')
+          }) }}
           <div class="row"><div class="columns">
             <label>
               {{ _('Description') }}