Include SubCategory Navigation

[xopj]

One of the biggest challenges I've seen with PRPL design in Ecommerce is overly simplifying the header navigation doesn't liken to real world example with multiple sub-category structures. First Meaningful Paint tends to rely heavily on getting the PDP's content elevated, but this gets derailed when the header requires the basic top levels, and then massive flyout menu's to appear. There's a mistrust in JSON loaded navigation due to the history with SEO, but I feel an enhancement in this demo to show a more elaborate navigation would be immensely beneficial. Thanks for considering, this codebase is an amazing learning tool!