Extensibility Walkthrough in capire (#405)

* Extension project template

* SalesRegion ->  x_SalesRegion

* enhanced order repo

* updated package-lock.json

orders-ext/app/extensions.cds

@@ -0,0 +1,25 @@
+namespace x_orders.ext; // for new entities like SalesRegion below
+using { OrdersService, sap, sap.capire.orders.Orders } from '@capire/orders';
+
+extend Orders with { // 2 new fields....
+  x_priority    : String enum {high; medium; low} default 'medium';
+  x_salesRegion : Association to x_SalesRegion;
+}
+
+entity x_SalesRegion : sap.common.CodeList { // Value Help
+  key code : String(11);
+}
+
+
+// -------------------------------------------
+// Fiori Annotations
+
+annotate Orders:x_priority with @title: 'Priority';
+annotate SalesRegion:name with @title: 'Sales Region';
+
+annotate OrdersService.Orders with @UI.LineItem: [
+  ... up to { Value: OrderNo },
+  { Value: x_priority },
+  { Value: x_salesRegion.name },
+  ...
+];