New Post: Custom Menu in C1

The easiest way is to create a page with the menu title "Shop" (I guess you already did this) and then add this in the page markup:

<f:function name="Composite.Web.Response.Redirect" xmlns:f="http://www.composite.net/ns/function/1.0">
        <f:param name="Url" value="https://compositec1.codeplex.com/" />
    </f:function>

When the user requests the page they will be redirected to the URL you specify.