Update README.md

README.md

@@ -24,6 +24,13 @@ You will need to get a Courier API key to get started. You can sign up and creat
 v6 of our SDK is automatically generated by [Fern](https://buildwithfern.com/). v6 comes
 with several improvements that we describe below: 
 
+- **Instantiate the client**: There is no longer one global CourierClient, instead you have to 
+  instantiate the client. 
+  ```ts
+  import { CourierClient } from "@trycourier/courier";
+
+  const courier = new CourierClient();
+  ```
 - **Resource-scoped SDK methods**: Endpoints are scoped under their resource. For 
   example, instead of `courier.deleteBrands` the SDK now reads `courier.brands.delete(...)`  
 - **Docs on Hover**: All endpoint and parameter level documentation that you see