Tweak description for group

Author: satya164

versioned_docs/version-6.x/group.md

@@ -4,7 +4,7 @@ title: Group
 sidebar_label: Group
 ---
 
-`Group` components are used to group several [screens](screen.md) inside a navigator.
+`Group` components are used to group several [screens](screen.md) inside a navigator for organizational purposes. They can also be used to apply the same options such as header styles to a group of screens.
 
 A `Group` is returned from a `createXNavigator` function:
 

versioned_docs/version-7.x/group.md

@@ -7,7 +7,7 @@ sidebar_label: Group
 import Tabs from '@theme/Tabs';
 import TabItem from '@theme/TabItem';
 
-A group contains several [screens](screen.md) inside a navigator.
+A group contains several [screens](screen.md) inside a navigator for organizational purposes. They can also be used to apply the same options such as header styles to a group of screens, or to define a common layout etc.
 
 <Tabs groupId="config" queryString="config">
 <TabItem value="static" label="Static" default>