ReadMe minor changes previous pr

Author: diazwatson

app/code/Magento/AdminNotification/README.md

@@ -8,11 +8,17 @@ Before disabling or uninstalling this module, note that the Magento_Indexer modu
 
 For information about module installation in Magento 2, see [Enable or disable modules](https://devdocs.magento.com/guides/v2.3/install-gde/install/cli/install-cli-subcommands-enable.html).
 
+## Extensibility
+
+Extension developers can interact with the Magento_AdminNotification module. For more information about the Magento extension mechanism, see [Magento plug-ins](https://devdocs.magento.com/guides/v2.3/extension-dev-guide/plugins.html).
+
+[The Magento dependency injection mechanism](https://devdocs.magento.com/guides/v2.3/extension-dev-guide/depend-inj.html) enables you to override the functionality of the Magento_AdminNotification module.
+
 ### Events
 
 This module observes the following events:
 
- - `controller_action_predispatch` event in `Magento\AdminNotification\Observer\PredispatchAdminActionControllerObserver`
+ - `controller_action_predispatch` event in `Magento\AdminNotification\Observer\PredispatchAdminActionControllerObserver` file.
 
 ### Layouts
 

app/code/Magento/AdvancedPricingImportExport/README.md

@@ -2,3 +2,8 @@
 
 The Magento_AdvancedPricingImportExport module handles the import and export of the advanced pricing.
 
+## Extensibility
+
+Extension developers can interact with the Magento_AdvancedPricingImportExport module. For more information about the Magento extension mechanism, see [Magento plug-ins](https://devdocs.magento.com/guides/v2.3/extension-dev-guide/plugins.html).
+
+[The Magento dependency injection mechanism](https://devdocs.magento.com/guides/v2.3/extension-dev-guide/depend-inj.html) enables you to override the functionality of the Magento_AdvancedPricingImportExport module.