GraphQL: Add configured_variant attribute

Author: keharper

src/guides/v2.4/graphql/interfaces/cart-item-interface.md

@@ -101,6 +101,7 @@ The `ConfigurableCartItem` object adds the following attributes to the `CartItem
 Attribute | Data type | Description
 --- | --- | ---
 `configurable_options` | [[SelectedConfigurableOption!]!](#SelectedConfigurableOption) | An array of configurable options
+`configured_variant` | [ProductInterface]({{page.baseurl}}/graphql/interfaces/product-interface.html) | Product details of the cart item
 `customizable_options` | [[SelectedCustomizableOption]](#SelectedCustomizableOption) | An array of customizable options the shopper chose for the configurable product
 
 ### SelectedConfigurableOption attributes {#SelectedConfigurableOption}