update zh-cn/application-dev/reference/apis/js-apis-app-ability-shareExtensionAbility.md.

fix format
Signed-off-by: Nxinking129 <xinxin13@huawei.com>

zh-cn/application-dev/reference/apis/js-apis-app-ability-shareExtensionAbility.md

@@ -100,7 +100,7 @@ ShareExtensionAbility生命周期回调，在销毁时回调，执行资源清
 
 3. ShareExtAbility.ts文件中，增加导入ShareExtensionAbility的依赖包，自定义类继承ShareExtensionAbility并实现生命周期回调。
 
-  ```ts
+   ```ts
    import ShareExtensionAbility from '@ohos.app.ability.ShareExtensionAbility';
    const TAG: string = "[ShareExtAbility]";