Update Hangfire document

docs/en/Background-Jobs-Hangfire.md

@@ -66,6 +66,8 @@ After you have installed these NuGet packages, you need to configure your projec
   }
 ````
 
+> You have to configure a storage for Hangfire.
+
 2. If you want to use hangfire's dashboard, you can add `UseHangfireDashboard` call in the `OnApplicationInitialization` method in `Module` class
 
 ````csharp

docs/en/Background-Workers-Hangfire.md

@@ -40,6 +40,8 @@ public class YourModule : AbpModule
 
 > Hangfire background worker integration provides an adapter `HangfirePeriodicBackgroundWorkerAdapter` to automatically load any `PeriodicBackgroundWorkerBase` and `AsyncPeriodicBackgroundWorkerBase` derived classes as `IHangfireBackgroundWorker` instances. This allows you to still to easily switch over to use Hangfire as the background manager even you have existing background workers that are based on the [default background workers implementation](Background-Workers.md).
 
+> You have to configure a storage for Hangfire.
+
 ## Create a Background Worker
 
 `HangfireBackgroundWorkerBase` is an easy way to create a background worker.

docs/zh-Hans/Background-Jobs-Hangfire.md

@@ -66,6 +66,8 @@ public class YourModule : AbpModule
   }
 ````
 
+> 你必须为Hangfire配置一个存储
+
 ### 指定队列
 
 你可以使用 [`QueueAttribute`](https://docs.hangfire.io/en/latest/background-processing/configuring-queues.html) 来指定队列.

docs/zh-Hans/Background-Workers-Hangfire.md

@@ -41,6 +41,8 @@ public class YourModule : AbpModule
 
 > Hangfire后台工作者集成提供了 `HangfirePeriodicBackgroundWorkerAdapter` 来适配 `PeriodicBackgroundWorkerBase` 和 `AsyncPeriodicBackgroundWorkerBase` 派生类. 所以你依然可以按照[后台工作者文档](Background-Workers.md)来定义后台作业.
 
+> 你必须为Hangfire配置一个存储
+
 ## 创建后台工作者
 
 `HangfireBackgroundWorkerBase` 是创建一个后台工作者简单的方法.