Shopify Provider (#186)

* Start of Shopify provider

* add missing comment to documentation

* add missing env vars to documentation

* update reference to types file

framework/shopify/product/get-product.ts

@@ -0,0 +1,37 @@
+import Client from 'shopify-buy'
+import { ShopifyConfig } from '../api'
+import { Product } from '../types'
+import toCommerceProducts from '../utils/to-commerce-products'
+
+export type ProductNode = Product
+
+type Variables = {
+  slug: string
+}
+
+type Options = {
+  variables: Variables
+  config: ShopifyConfig
+  preview?: boolean
+}
+
+type ReturnType = {
+  product: any
+}
+
+const getProduct = async (options: Options): Promise<ReturnType> => {
+  const { variables, config } = options
+
+  const client = Client.buildClient({
+    storefrontAccessToken: config.apiToken,
+    domain: config.commerceUrl,
+  })
+
+  const res = (await client.product.fetchByHandle(variables.slug)) as Product
+
+  return {
+    product: toCommerceProducts([res])[0],
+  }
+}
+
+export default getProduct