I've been meaning to do a showhn on this, but this is pretty much exactly what I've been working on. https://www.reciped.io . Sort of a wikipedia of recipes, everything in markdown, add recipes to your recipe book, and then it's drag and drop weekly meal planning. Grocery list gets autopopulated by the meals in your weekly list and sorted by section in the grocery store (produce, meat, dairy, spice aisle, frozen foods, ect). Grocery list itself is built for mobile, so you just swipe the item off the list as you grab it at the store.