update docs

Signed-off-by: Nge-yafang <geyafang@huawei.com>

en/application-dev/device/usb-guidelines.md

@@ -35,60 +35,60 @@ You can set a USB device as the USB host to connect to other USB devices for dat
 1.  Obtain the USB device list.
 
     ```js
-        // Import the USB API package.
-        import usb from '@ohos.usbV9';
-        // Obtain the USB device list.
-        let deviceList = usb.getDevices();
-        /*
-        Example deviceList structure
-        [
+    // Import the USB API package.
+    import usb from '@ohos.usbV9';
+    // Obtain the USB device list.
+    let deviceList = usb.getDevices();
+    /*
+    Example deviceList structure
+    [
+      {
+        name: "1-1",
+        serial: "",
+        manufacturerName: "",
+        productName: "",
+        version: "",
+        vendorId: 7531,
+        productId: 2,
+        clazz: 9,
+        subclass: 0,
+        protocol: 1,
+        devAddress: 1,
+        busNum: 1,
+        configs: [
           {
+            id: 1,
+            attributes: 224,
+            isRemoteWakeup: true,
+            isSelfPowered: true,
+            maxPower: 0,
             name: "1-1",
-            serial: "",
-            manufacturerName: "",
-            productName: "",
-            version: "",
-            vendorId: 7531,
-            productId: 2,
-            clazz: 9,
-            subclass: 0,
-            protocol: 1,
-            devAddress: 1,
-            busNum: 1,
-            configs: [
+            interfaces: [
               {
-                id: 1,
-                attributes: 224,
-                isRemoteWakeup: true,
-                isSelfPowered: true,
-                maxPower: 0,
+                id: 0,
+                protocol: 0,
+                clazz: 9,
+                subclass: 0,
+                alternateSetting: 0,
                 name: "1-1",
-                interfaces: [
+                endpoints: [
                   {
-                    id: 0,
-                    protocol: 0,
-                    clazz: 9,
-                    subclass: 0,
-                    alternateSetting: 0,
-                    name: "1-1",
-                    endpoints: [
-                      {
-                        address: 129,
-                        attributes: 3,
-                        interval: 12,
-                        maxPacketSize: 4,
-                        direction: 128,
-                        number: 1,
-                        type: 3,
-                        interfaceId: 0,
-                     }
-                   ]
-                 }
-               ]
-             }
-           ]
-         }
-       ]
+                    address: 129,
+                    attributes: 3,
+                    interval: 12,
+                    maxPacketSize: 4,
+                    direction: 128,
+                    number: 1,
+                    type: 3,
+                    interfaceId: 0,
+                  }
+                ]
+              }
+            ]
+          }
+        ]
+      }
+    ]
     */
     ```