Make 4.x explicit and add another include instance

Author: ggailey777

articles/azure-functions/extension-bundles.md

@@ -55,7 +55,9 @@ Keep these considerations in mind when you work with extension bundles:
 
 It's important to keep your bundle version up-to-date so that your apps can continue to be eligible for new features, security patches, and performance optimizations. 
 
-To upgrade your app to the most recent bundle, edit the host.json file in the root of your app project. Replace the value of `extensionBundle.version` with the most recent supported extension bundles version.
+To upgrade your app to the most recent bundle, edit the host.json file in the root of your app project. Set the value of `extensionBundle.version` to `[4.x,5.0.0)`, which should look like this in your host.json file:
+
+[!INCLUDE [functions-extension-bundles-json](../../includes/functions-extension-bundles-json.md)]
 
 Keep these considerations in mind when upgrading the extension bundle version used by your app: