feat: implement periodic shopify sales sync

- automated sales check (default 10 mins)

- manual reconciliation menu

- updates 'status' and 'shopify_status' in sheet

- updated docs

src/shopifyApi.ts

@@ -482,6 +482,48 @@ export class Shop {
     } while (!done)
   }
 
+  FetchOrders(start: Date, end: Date) {
+    let endpoint = Shop.endpoints.orders
+    let start_str = start.toISOString()
+    let end_str = end.toISOString()
+    var params = {
+      created_at_min: start_str,
+      created_at_max: end_str,
+      fields: "id,created_at,financial_status,name,line_items,subtotal_price,total_price,total_tax",
+      status: "any"
+    }
+
+    var all_orders: any[] = []
+    var done = false
+    var next_link = ""
+    do {
+      var response
+      if (next_link === "") {
+        response = this.shopifyAPI(endpoint, params)
+      } else {
+        response = this.shopifyAPI(endpoint, params, next_link)
+      }
+      let resp = response.content
+      let headers = response.headers
+      var orders_arr = resp["orders"]
+      if (orders_arr.length > 0) {
+        all_orders = all_orders.concat(orders_arr)
+      }
+
+      if (headers["Link"] !== undefined) {
+        var links = parseLinkHeader(headers["Link"])
+        if (links["next"] === undefined) {
+          done = true
+        } else {
+          next_link = links["next"]["href"]
+        }
+      } else {
+        done = true
+      }
+    } while (!done)
+    return all_orders
+  }
+
   GetProducts() {
     let done = false
     let query = ""