Listing materials now available

Katana API has a new resource available - materials. It's currently only possible to receive the materials list, but the creation, update, and deletion of materials are on the roadmap to come out later. With this update, we also added a material_id field to variants. Variants are mapped to either a product or a material, depending on the type.

Materials are the items used in manufacturing products. Similar to products, materials have variants. Creating material allows you to add it to product recipes, purchase orders and to keep track of its inventory levels.