add next previous

dashboard-v4/dashboard/src/locales/en-US/buttons.ts

@@ -105,6 +105,8 @@ const items = {
   "buttons.task.add.next-task": "next task",
   "buttons.remove.milestone": "remove milestone",
   "buttons.set.milestone": "set as milestone",
+  "buttons.next": "Next",
+  "buttons.previous": "Previous",
 };
 
 export default items;

dashboard-v4/dashboard/src/locales/zh-Hans/buttons.ts

@@ -106,6 +106,8 @@ const items = {
   "buttons.task.add.next-task": "添加后置任务",
   "buttons.remove.milestone": "移除里程碑",
   "buttons.set.milestone": "设置为里程碑",
+  "buttons.next": "下一步",
+  "buttons.previous": "上一步",
 };
 
 export default items;