Extensibility Walkthrough in capire (#405)

* Extension project template

* SalesRegion ->  x_SalesRegion

* enhanced order repo

* updated package-lock.json

orders-ext/README.md

@@ -0,0 +1,26 @@
+# Getting Started
+
+Welcome to your extension project to  `@capire/orders`.
+
+It contains these folders and files, following our recommended project layout:
+
+File or Folder | Purpose
+---------|----------
+`app/` | all extensions content is here
+`test/` | all test content is here
+`package.json` | project configuration
+`readme.md` | this getting started guide
+
+
+## Next Steps
+
+- `cds pull` latest models from your base application
+- edit [`./app/extensions.cds`](./app/extensions.cds) to add your extensions
+- `cds watch` your extension in local test-drives
+- `cds push` your extension to **test** tenant 
+- `cds push` your extension to **prod** tenant  
+
+
+## Learn More
+
+Learn more at https://cap.cloud.sap/docs/guides/extensibility/customization.