update docs

Signed-off-by: NAnnie_wang <annie.wangli@huawei.com>

en/application-dev/reference/apis/js-apis-filemanager.md

@@ -3,6 +3,7 @@
 >
 >- The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
 >- The APIs of this module are system APIs and cannot be called by third-party applications. Currently, these APIs can be called only by **filepicker**.
+
 ## Modules to Import
 
 ```js
@@ -20,7 +21,7 @@ Obtains information about the files in the first-level directory in asynchronous
 - Parameters
   | Name| Type| Mandatory| Description|
   | --- | --- | --- | -- |
-  | dev | [DevInfo](#devinfo) | No| Device name. The default value is **local**, which is the only value supported.|
+  | options | Object | No| The options are as follows:<br>- &nbsp;**dev**: Device type. For details, see [DevInfo](#devinfo). It is **dev = {name: "local"}** by default if not specified. Currently, only 'local' is supported.|
 
 - Return value
 
@@ -30,17 +31,17 @@ Obtains information about the files in the first-level directory in asynchronous
 
 - Example
 
-```js
-filemanager.getRoot().then((fileInfo) => {
-    if(Array.isArray(fileInfo)) {
-        for (var i = 0; i < fileInfo.length; i++) {
-            console.log(JSON.Stringify(fileInfo))
-        }
-    }
-}).catch((err) => {
-    console.log(err)
-});
-```
+  ```js
+  filemanager.getRoot().then((fileInfo) => {
+      if(Array.isArray(fileInfo)) {
+          for (var i = 0; i < fileInfo.length; i++) {
+              console.log(JSON.Stringify(fileInfo))
+          }
+      }
+  }).catch((err) => {
+      console.log(err)
+  });
+  ```
 
 ## filemanager.getRoot
 
@@ -54,20 +55,20 @@ Obtains information about the files in the first-level directory in asynchronous
 
   | Name  | Type                     | Mandatory| Description                         |
   | -------- | ------------------------- | ---- | ----------------------------- |
-  | dev      | [DevInfo](#devinfo)              | No  | Device name. The default value is **local**, which is the only value supported.|
+  | options | Object | No| The options are as follows:<br>- &nbsp;**dev**: Device type. For details, see [DevInfo](#devinfo). It is **dev = {name: "local"}** by default if not specified. Currently, only 'local' is supported.|
   | callback | AsyncCallback&lt;[FileInfo](#fileinfo)[]&gt; | Yes  | Callback invoked to return the file information obtained. |
 
 - Example
 
-```js
-filemanager.getRoot((err, fileInfo) => {
-    if(Array.isArray(fileInfo)) {
-        for (var i = 0; i < fileInfo.length; i++) {
-            console.log(JSON.Stringify(fileInfo))
-        }
-    }
-})
-```
+  ```js
+  filemanager.getRoot((err, fileInfo) => {
+      if(Array.isArray(fileInfo)) {
+          for (var i = 0; i < fileInfo.length; i++) {
+              console.log(JSON.Stringify(fileInfo))
+          }
+      }
+  });
+  ```
 
 ## filemanager.listFile
 
@@ -80,12 +81,10 @@ Obtains information about the files in the second-level directory in asynchronou
 - Parameters
   | Name| Type| Mandatory| Description|
   | --- | --- | --- | -- |
-  | type | string | Yes| Type of the files to query. The file type can be **file**, **image**, **audio**, or **video**.|
   | path | string | Yes| URI of the directory to query.|
-  | dev | [DevInfo](#devinfo) | Yes| Device name. The default value is **local**, which is the only value supported.|
-  | offset | number | No| Start position from which the files are to query.|
-  | count | number | No| Number of files to query.|
-
+  | type | string | Yes| Type of the files to query. The file type can be **file**, **image**, **audio**, or **video**.|
+  | options | Object | No| The options are as follows:<br>- &nbsp;**dev**: Device type. For details, see [DevInfo](#devinfo). It is **dev = {name: "local"}** by default if not specified. Currently, only 'local' is supported.<br>- &nbsp;**offset**: position to start the query. The value is a number.<br>- &nbsp;**count**: number of files to query.|
+  
 - Return value
 
   | Type| Description|
@@ -94,26 +93,29 @@ Obtains information about the files in the second-level directory in asynchronou
 
 - Error
   | Error Info| Error Code|Description|
-  | --       | ---    | -- |
-  |No such file or directory | 2      | The directory or file of the specified URI does not exist.|
-  |No such process | 3 | Failed to obtain the FMS service.|
-  |Not a directory | 20 | The object specified by the URI is not a directory.|
+  | -- | --- | -- |
+  | No such file or directory | 2      | The directory or file of the specified URI does not exist.|
+  | No such process | 3 | Failed to obtain the FMS service.|
+  | Not a directory | 20 | The object specified by the URI is not a directory.|
+
+- Example
+
+  ```js
+  // Obtain all files in the directory.
+  // Call listFile() and getRoot() to obtain file URIs.
+  let media_path = file.uri
+  filemanager.listFile(media_path, "file")
+  .then((fileInfo) => {
+      if(Array.isArray(fileInfo)) {
+          for (var i = 0; i < fileInfo.length; i++) {
+              console.log(JSON.Stringify(fileInfo))
+          }
+      }
+  }).catch((err) => {
+      console.log(err)
+  });
+  ```
 
-```js
-// Obtain all files in the directory.
-// Call listFile() and getRoot() to obtain file URIs.
-let media_path = file.uri
-filemanager.listFile(media_path, "file")
-.then((fileInfo) => {
-    if(Array.isArray(fileInfo)) {
-        for (var i = 0; i < fileInfo.length; i++) {
-            console.log(JSON.Stringify(fileInfo))
-        }
-    }
-}).catch((err) => {
-    console.log(err)
-})
-```
 ## filemanager.listFile
 
 listFile(path : string, type : string, options? : {dev? : DevInfo, offset? : number, count? : number}, callback : AsyncCallback&lt;FileInfo[]&gt;) : void
@@ -126,35 +128,35 @@ Obtains information about the files in the second-level directory in asynchronou
 
   | Name  | Type                     | Mandatory| Description                                                        |
   | -------- | ------------------------- | ---- | ------------------------------------------------------------ |
-  | type     | string                    | Yes  | Type of the files to query. The file type can be **file**, **image**, **audio**, or **video**.|
   | path     | string                    | Yes  | URI of the directory to query.                                               |
-  | dev | [DevInfo](#devinfo) | No| Device name. The default value is **local**, which is the only value supported.|
-  | offset | number | No| Start position from which the files are to query.|
-  | count | number | No| Number of files to query.|
+  | type     | string                    | Yes  | Type of the files to query. The file type can be **file**, **image**, **audio**, or **video**.|
+  | options | Object | No| The options are as follows:<br>- &nbsp;**dev**: Device type. For details, see [DevInfo](#devinfo). It is **dev = {name: "local"}** by default if not specified. Currently, only 'local' is supported.<br>- &nbsp;**offset**: position to start the query. The value is a number.<br>- &nbsp;**count**: number of files to query.|
   | callback | AsyncCallback&lt;[FileInfo](#fileinfo)[]&gt; | Yes  | Callback invoked to return the file information obtained.                                |
 - Error
 
   | Error Info                 | Error Code| Description                     |
   | ------------------------- | ------ | ------------------------- |
-  |No such file or directory  | 2      | The directory or file of the specified URI does not exist.|
-  |No such process            | 3      | Failed to obtain the FMS service.          |
-  |Not a directory            | 20     | The object specified by the URI is not a directory.|
+  | No such file or directory | 2      | The directory or file of the specified URI does not exist.|
+  | No such process           | 3      | Failed to obtain the FMS service.          |
+  | Not a directory           | 20     | The object specified by the URI is not a directory.|
 
-```js
-// Call listFile() and getRoot() to obtain the file UIRs.
-let media_path = file.uri
-filemanager.listFile(media_path, "file", (err, fileInfo) => {
-    if(Array.isArray(fileInfo)) {
-        for (var i = 0; i < fileInfo.length; i++) {
-            console.log(JSON.Stringify(fileInfo))
-        }
-    }
-})
-```
+- Example
+
+  ```js
+  // Call listFile() and getRoot() to obtain file URIs.
+  let media_path = file.uri
+  filemanager.listFile(media_path, "file", (err, fileInfo) => {
+      if(Array.isArray(fileInfo)) {
+          for (var i = 0; i < fileInfo.length; i++) {
+              console.log(JSON.Stringify(fileInfo))
+          }
+      }
+  });
+  ```
 
 ## filemanager.createFile
 
-filemanager.createFile(path : string, filename : string, options? : {dev? : DevInfo})  :   promise&lt;string&gt;
+filemanager.createFile(path : string, filename : string, options? : {dev? : DevInfo})  :   Promise&lt;string&gt;
 
 Creates a file in the specified path in asynchronous mode. This method uses a promise to return the result.
 
@@ -165,7 +167,7 @@ Creates a file in the specified path in asynchronous mode. This method uses a pr
   | --- | --- | --- | -- |
   | filename | string | Yes| Name of the file to create.|
   | path | string | Yes| URI of the file to create.|
-  | dev | [DevInfo](#devinfo) | No| Device name. The default value is **local**, which is the only value supported.|
+  | options | Object | No| The options are as follows:<br>- &nbsp;**dev**: Device type. For details, see [DevInfo](#devinfo). It is **dev = {name: "local"}** by default if not specified. Currently, only 'local' is supported.|
 
 - Return value
 
@@ -181,18 +183,20 @@ Creates a file in the specified path in asynchronous mode. This method uses a pr
   | No such process | 3 | Failed to obtain the FMS service.|
   | Not a directory | 20 | The object specified by the URI is not a directory.|
 
-```js
-// Create a file.
-let media_path = file.uri // Obtain the file URI using listFile() and getRoot().
-let name = "xxx.jpg" // File to be saved.
-filemanager.createFile(media_path, name)
-.then((uri) => {
-// The URI of the file created is returned.
-})
-.catch((err) => {
-    console.log(err)
-})
-```
+- Example
+
+  ```js
+  // Create a file.
+  let media_path = file.uri // Obtain the file URI using listFile() and getRoot().
+  let name = "xxx.jpg" // File to be saved.
+  filemanager.createFile(media_path, name)
+  .then((uri) => {
+  // The URI of the file created is returned.
+  })
+  .catch((err) => {
+      console.log(err)
+  });
+  ```
 
 ## filemanager.createFile
 
@@ -208,7 +212,7 @@ Creates a file in the specified path in asynchronous mode. This method uses a ca
   | -------- | ------------------------- | ---- | ----------------------------- |
   | filename | string                    | Yes  | Name of the file to create.               |
   | path     | string                    | Yes  | URI of the file to create.            |
-  | dev | [DevInfo](#devinfo) | No| Device name. The default value is **local**, which is the only value supported.|
+  | options | Object | No| The options are as follows:<br>- &nbsp;**dev**: Device type. For details, see [DevInfo](#devinfo). It is **dev = {name: "local"}** by default if not specified. Currently, only 'local' is supported.|
   | callback | AsyncCallback&lt;[FileInfo](#fileinfo)[]&gt; | Yes  | Callback invoked to return the file information obtained. |
 
 - Error
@@ -220,16 +224,18 @@ Creates a file in the specified path in asynchronous mode. This method uses a ca
   | No such process           | 3      | Failed to obtain the FMS service.          |
   | Not a directory           | 20     | The object specified by the URI is not a directory.|
 
-```js
-// Create a file.
-// Call listFile() and getRoot() to obtain the file URI.
-let media_path = file.uri
-// File to be saved.
-let name = "xxx.jpg"
-filemanager.createFile(media_path, name, (err, uri) => {
-// The URI of the file created is returned.
-})
-```
+- Example
+
+  ```js
+  // Create a file.
+  // Call listFile() and getRoot() to obtain the file URI.
+  let media_path = file.uri
+  // File to be saved.
+  let name = "xxx.jpg"
+  filemanager.createFile(media_path, name, (err, uri) => {
+  // The URI of the file created is returned.
+  });
+  ```
 
 ## FileInfo
 Defines the file information returned by **getRoot()** or **listFile()**.
@@ -248,12 +254,13 @@ Defines the file information returned by **getRoot()** or **listFile()**.
 | modifiedTime | number | Yes| No| Time when the file was modified.|
 
 ## DevInfo
+
 Defines the device type.
 
 **System capability**: SystemCapability.FileManagement.FileManagerService
 
 ### Attributes
 
-  | Name| Type| Readable| Writable| Description|
-  | --- | -- | -- | -- | -- |
-  | name | string | Yes| Yes| Device name.|
+| Name| Type  | Readable| Writable| Description    |
+| ------ | ------ | ---- | ---- | -------- |
+| name   | string | Yes  | Yes  | Device name.|