The most obvious way to make a new feature available to users is by adding a menu item. When you click on a menu item, something happens. This recipe walks you through how to define that something.

We will create a top-level menu and its sub-menu, which will open a list of all customers.

This can also be done using the web user interface, through the settings menu, but we prefer to use XML data files since this is what we'll have to use when creating our add-on modules.