update docs against 5824

Signed-off-by: Nwusongqing <wusongqing@huawei.com>

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

 # Screenshot
+Provides APIs for you to set information such as the region to capture and the size of the screen region when capturing a screen.
 
 >  **NOTE**
 >
 > The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.
+>
+> The APIs provided by this module are system APIs.
 
 ## Modules to Import
 
@@ -17,11 +20,12 @@ Describes screenshot options.
 **System capability**: SystemCapability.WindowManager.WindowManager.Core
 
 
-| Name    | Type         | Mandatory| Description                                                        |
-| ---------- | ------------- | ---- | ------------------------------------------------------------ |
-| screenRect | [Rect](#rect) | No  | Region of the screen to capture. If this parameter is null, the full screen will be captured.|
-| imageSize  | [Size](#size) | No  | Size of the screen region to capture. If this parameter is null, the full screen will be captured.|
-| rotation   | number        | No  | Rotation angle of the screenshot. Currently, the value can be **0** only. The default value is **0**.|
+| Name                | Type         | Mandatory| Description                                                        |
+| ---------------------- | ------------- | ---- | ------------------------------------------------------------ |
+| screenRect             | [Rect](#rect) | No  | Region of the screen to capture. If this parameter is null, the full screen will be captured.                      |
+| imageSize              | [Size](#size) | No  | Size of the screen region to capture. If this parameter is null, the full screen will be captured.                      |
+| rotation               | number        | No  | Rotation angle of the screenshot. Currently, the value can be **0** only. The default value is **0**.    |
+| displayId<sup>8+</sup> | number        | No  | ID of the [display](js-apis-display.md#display) device on which the screen region is to be captured.|
 
 
 ## Rect
@@ -63,7 +67,7 @@ Takes a screenshot and saves it as a **PixelMap** object. This method uses a cal
 
 | Name  | Type                                   | Mandatory| Description                                                        |
 | -------- | --------------------------------------- | ---- | ------------------------------------------------------------ |
-| options  | [ScreenshotOptions](#screenshotoptions) | No  | Screenshot options, which consist of **screenRect**, **imageSize**, and **rotation**. You need to set these parameters.|
+| options  | [ScreenshotOptions](#screenshotoptions) | No  | Consists of **screenRect**, **imageSize**, **rotation**, and **displayId**. You can set them separately.|
 | callback | AsyncCallback&lt;image.PixelMap&gt;     | Yes  | Callback used to return a **PixelMap** object.                                  |
 
 **Example**
@@ -78,7 +82,8 @@ Takes a screenshot and saves it as a **PixelMap** object. This method uses a cal
   	"imageSize": {
   		"width": 300,
   		"height": 300},
-  	"rotation": 0
+  	"rotation": 0,
+  	"displayId": 0
   };
   screenshot.save(ScreenshotOptions, (err, data) => {
   	if (err) {
@@ -103,13 +108,13 @@ Takes a screenshot and saves it as a **PixelMap** object. This method uses a pro
 
 | Name | Type                                   | Mandatory| Description                                                        |
 | ------- | --------------------------------------- | ---- | ------------------------------------------------------------ |
-| options | [ScreenshotOptions](#screenshotoptions) | No  | Screenshot options, which consist of **screenRect**, **imageSize**, and **rotation**. You need to set these parameters.|
+| options | [ScreenshotOptions](#screenshotoptions) | No  | Consists of **screenRect**, **imageSize**, **rotation**, and **displayId**. You can set them separately.|
 
 **Return value**
 
 | Type                         | Description                                           |
 | ----------------------------- | ----------------------------------------------- |
-| Promise&lt;image.PixelMap&gt; | Promise used to return an **image.PixelMap** object.|
+| Promise&lt;image.PixelMap&gt; | Promise used to return a **PixelMap** object.|
 
 **Example**
 
@@ -123,7 +128,8 @@ Takes a screenshot and saves it as a **PixelMap** object. This method uses a pro
   	"imageSize": {
   		"width": 300,
   		"height": 300},
-  	"rotation": 0
+  	"rotation": 0,
+  	"displayId": 0
   };
   let promise = screenshot.save(ScreenshotOptions);
   promise.then(() => {