This will be the component that renders the additional items for sale from the seller.
Port: Set up to use process.env.ADDITIONAL_ITEMS_PORT variable. Defaults to 3004 if the .env is not set up.
Server start script: npm start
Build script: npm run build
Database seeding script: npm run seed
CRUD API routes
GET items for a seller '/additional'
DELETE an item '/additional/:id'
PUT update an item '/additional/:id'
POST a new item '/additional'