Update custom_control.md

Author: oblomov-dev

docs/advanced/extensibility/custom_control.md

@@ -1,3 +1,14 @@
-# Custom Controls
+# Custom Controls  
 
-You can develop your own UI5 custom controls and integrate them with the ABAP backend. Check out [this guideline](https://community.sap.com/t5/technology-blogs-by-members/abap2ui5-11-extensions-ii-guideline-for-developing-new-features-in/ba-p/13576797) to learn more.
+You can develop your own UI5 custom controls and use them in your abap2UI5 apps.
+
+Set up your VS Code environment with the abap2UI5 frontend artifacts as described in the frontend chapter.  
+
+#### Frontend
+
+Create the JS code for your new custom control. You can copy and paste an existing custom control of this file and adjust it to your needs:  
+https://github.com/abap2UI5/abap2UI5/blob/main/app/webapp/controller/App.controller.js
+
+#### Backend  
+Extend the custom control view class by adding an additional method and defining the properties of your custom control here:  
+z2ui5_cl_xml_view_cc.clas.abap](https://github.com/abap2UI5/abap2UI5/blob/main/src/02/z2ui5_cl_xml_view_cc.clas.abap