We carry different brands and would like to be able to add products from these different brands onto a single shopping page in the "Women", "Men", "Accessories", and "Home" categories. Currently, we are only able to have individual shops, and we can't figure out how to mix products from the different shops onto a single shopping page. For example, we carry women's products from the brands Basader, Big Z & Co. and NMB New York, and we want to create a single multi-vendor shopping page where all of these products can be viewed. Can you explain how to do this?