chore: Update README.md

Author: cbetta

README.md

@@ -1,5 +1,9 @@
 # Gr4vy SDK for Node
 
+<br /><br />
+> [!IMPORTANT]
+> This SDK will be deprecated soon. Please refer to our new [Beta Typescript SDK](https://github.com/gr4vy/gr4vy-python/tree/legacy) for the new direction for this SDK.
+
 [![Module Version](https://badge.fury.io/js/%40gr4vy%2Fnode.svg)][npm]
 
 Gr4vy provides any of your payment integrations through one unified API. For more details, visit [gr4vy.com](https://gr4vy.com).