Allow CustomLink type to create link menus

[akademy]

Allow creation of the menu items, currently only in NavBar and Footer, to be created with an array of CustomLink types.

export type CustomLink = {
    name: string;
    href: string;
}

e.g. Something like:

const myLinks: CustomLink[] = [{
    "name":"menu one",
    "href":"/menu/one/"
}]
<NavBar menu={my-links} />

[akademy]

We need to review whether it makes sense to have separate NavLinks and FooterLinks. And whether it then makes sense to also use CustomLink (which is currently only used in Breadcrumbs) to make links.