Just found this the release candidate and haven't really seen it mentioned anywhere.

If you go into Reminders and select list > Show Lift Info

there is now a List Type setting that can be set to 'Shopping'. If you do that, the contents of the list will automagically organise themselves under sub-headings - e.g, in my case

• Beverages
• Dairy, Eggs & Cheese
• Deli
• Fruit & Veg
• Household items
• Spices & Seasonings

... etc

These headings are dynamically created. Its quite night and saved me a bit of time on my weekly shop.