修改fetch格式问题

Signed-off-by: Nxujie <xujie223@huawei.com>

zh-cn/application-dev/reference/apis/js-apis-system-fetch.md

@@ -22,43 +22,36 @@ fetch(options:{
      * @since 3
      */
     url: string;
-  
     /**
      * Request parameter, which can be of the string type or a JSON object.
      * @since 3
      */
     data?: string | object;
-  
     /**
      * Request header, which accommodates all attributes of the request.
      * @since 3
      */
     header?: Object;
-  
     /**
      * Request methods available: OPTIONS, GET, HEAD, POST, PUT, DELETE and TRACE. The default value is GET.
      * @since 3
      */
     method?: string;
-  
     /**
      * The return type can be text, or JSON. By default, the return type is determined based on Content-Type in the header returned by the server.
      * @since 3
      */
     responseType?: string;
-  
     /**
      * Called when the network data is obtained successfully.
      * @since 3
      */
     success?: (data: FetchResponse) => void;
-  
     /**
      * Called when the network data fails to be obtained.
      * @since 3
      */
     fail?: (data: any, code: number) => void;
-  
     /**
      * Called when the execution is completed.
      * @since 3