docs(setup): add next steps section for architecture customization

- Introduce a new section "Next Steps: Customize Your Toolkit"
- Celebrate the successful local setup
- Encourage exploration of architecture and customization
- Provide a link to the "Architecture & Customization" section

Author: fulleni

src/content/docs/local-setup.mdx

@@ -28,3 +28,11 @@ We recommend following the guides in the order presented to ensure a smooth setu
 
     [Go to Mobile App Setup Guide →](/docs/mobile-client/local-setup/)
 </Steps>
+
+### Next Steps: Customize Your Toolkit
+
+Congratulations! You now have the entire toolkit running locally. This is the perfect time to explore the architecture and learn how to make it your own.
+
+The next logical step is to dive into our **Architecture & Customization** section, where you will learn how to take ownership of the shared packages and begin customizing your applications.
+
+[**Go to Architecture & Customization &rarr;**](/docs/architecture/)