Update index.md

docs/en/tutorials/modular-crm/index.md

@@ -1,8 +1,18 @@
 # Modular Monolith Application Development Tutorial
 
+````json
+//[doc-nav]
+{
+  "Next": {
+    "Name": "Creating the initial solution",
+    "Path": "tutorials/modular-crm/part-01"
+  }
+}
+````
+
 ABP provides a great infrastructure and tooling to build modular software solutions. In this tutorial, you will learn how to create application modules, compose and communicate them to build a monolith modular web application.
 
-> **This tutorial is focused on modularity. The example application's functionality and user interface are intentionally kept simple. If you want to learn real world, full featured application development with ABP, please follow the [Book Store tutorial](../book-store/index.md).**
+> **This tutorial focuses on modularity.** The example application's functionality and user interface are intentionally kept simple. If you want to learn real world, full featured application logic development with ABP, please follow the [Book Store tutorial](../book-store/index.md).
 
 ## Tutorial Outline