Update upgrade-to-4.0.md

docs/upgrade-to-4.0.md

@@ -23,7 +23,9 @@ Should now become this:
 ### Header
 
 The header implementation has been simplified and a reduced set of components are on offer for this version.
+
 The `Header.NavContainer`, `Header.NavItemList`, and `Header.NavTitle` components have been removed. Instead, the `Header.Nav` component includes the container for rendering items. The nav title has been removed, and customisation of the dropdown manu link text can be done via the `dropdownText` prop on the new `Header.NavDropdownMenu` component.
+
 The `Header.MenuToggle` and `Header.NavMenuClose` components have been removed. Instead, these should be replaced with a usage of `Header.NavDropdownMenu` added as the last child of `Header.NavMenu`.
 
 For example, this: