Update Magento_AdminNotification module ReadMe

app/code/Magento/AdminNotification/README.md

@@ -1,4 +1,30 @@
-# Admin Notification
+# Magento_AdminNotification module
 
-**Admin Notification** provides the ability to alert administrators via
-system messages and provides a message inbox for surveys and notifications.
+The Magento_AdminNotification module provides the ability to alert administrators via system messages and provides a message inbox for surveys and notifications.
+
+## Installation details
+
+Before disabling or uninstalling this module, note that the Magento_Indexer module depends on this module.
+
+For information about module installation in Magento 2, see [Enable or disable modules](http://devdocs.magento.com/guides/v2.3/install-gde/install/cli/install-cli-subcommands-enable.html).
+
+### Events
+
+This module observes the following events:
+
+ - `controller_action_predispatch` event in `Magento\AdminNotification\Observer\PredispatchAdminActionControllerObserver`
+
+### Layouts
+
+This module introduces the following layouts and layout handles in the `view/adminhtml/layout` directory:
+
+- `adminhtml_notification_index`
+- `adminhtml_notification_block`
+
+For more information about layouts in Magento 2, see the [Layout documentation](http://devdocs.magento.com/guides/v2.3/frontend-dev-guide/layouts/layout-overview.html).
+
+### UI components
+
+You can extend admin notifications using the `view/adminhtml/ui_component/notification_area.xml` configuration file.
+
+For information about UI components in Magento 2, see [Overview of UI components](http://devdocs.magento.com/guides/v2.3/ui_comp_guide/bk-ui_comps.html).