Update README.md with deprecation message

Author: ryanio

README.md

@@ -11,6 +11,9 @@
 
 # OpenSea Stream API - TypeScript SDK
 
+> [!IMPORTANT]  
+> The OpenSea Stream API has been deprecated. Please refer to our [documentation](https://docs.opensea.io/reference/api-overview) for the latest - you can replace usage with [Get Events](https://docs.opensea.io/reference/list_events).
+
 A TypeScript SDK for receiving updates from the OpenSea Stream API - pushed over websockets. We currently support the following event types on a per-collection basis:
 
 - item listed