Function items_for 

pub fn items_for(
    xdg_root: Option<&Path>,
    platform_config: Option<&Path>,
    platform_data: Option<&Path>,
    home: &Path,
) -> Vec<Item>

The old-to-new list for the given old roots and new home. xdg_root is ~/.config/scope; the platform roots are the folders above their scope subfolder.