Doc feature: Release Detail (#364)

Help user to know the capability of Helm-Dashboard

FEATURES.md

@@ -46,4 +46,12 @@ Namespaces are a way to organize clusters into virtual sub-clusters — they can
 ![Releases4](images/screenshot_release4.png)
 
 Updated" refers to the amount of time that has passed since the last revision of the release. Whenever you install or upgrade the release, a new revision is created. You can think of it as the "age" of the latest revision.
-![Releases5](images/screenshot_release5.png)
+![Releases5](images/screenshot_release5.png)
+
+# Release details
+This indicates the status of the deployed release, and 'Age' represents the amount of time that has passed since the creation of the revision until now.
+![Detail](images/screenshot_release_detail.png)
+
+You can use the Upgrade/Downgrade button to switch to different release versions, as shown in the figure.
+![Detail1](images/screenshot_release_detail1.png)
+