1. Provide a region's product inventory level
 2. Move interfaces into their own directory.
 3. Add property "ineligibleRegion"
 4. Add property product.offers.priceSpecfication to indicate 
    delivery & pickup charges.
 5. Refactor: move-up deliveryMethodMap to provide DeliveryMethod
    enumerations to multiple resources.
 6. Add property product.offers.availableAtOrFrom to indicate the
    place(s) from which the offer can be obtained (e.g. store 
    locations).
    @See https://schema.org/availableAtOrFrom
 7. Remove unused devDependencies
 8. Enrich a product by adapting Home Depot's 
    productClientOnlyProject GraphQL result to match 
    schema.org/inventoryLevel on a product's "offers" property.
 9. Refactor:move-up all modules and remove the /src/crawlers/hd/ 
    directory.
10. Create a single module exports resource (/src/index).

Closes #10