feat: explore English version doc (#6)

en/SUMMARY.md

@@ -33,6 +33,7 @@
 
 ## Explore
 
+* [Discovery](explore/app.md)
 * [Chat](explore/chat.md)
 
 ## Advanced

en/explore/app.md

@@ -0,0 +1,15 @@
+# Discovery
+## Template application
+In **Explore > Discovery**, some commonly used template applications are provided. These apps cover translate, writing, programming and assistant.
+![](./images/explore-app.jpg)
+
+If you want to use a template application, click the template's "Add to Workspace" button. In the workspace on the left, the app is available.
+![](./images/creat-customize-app.jpg)
+
+If you want to modify a template to create a new application, click the "Customize" button of the template.
+
+## Workspace
+The workspace is the application's navigation. Click an application in the workspace to use the application directly.
+![](./images/workspace.jpg)
+
+Apps in the workspace include: your own apps and apps added to the workspace by other teams.