Update README.md to include transfer details

Author: paulasjes-stripe

README.md

@@ -1,3 +1,7 @@
+# UPDATE 2023-08-11:
+This project is in the process of being transferred to [Invertase](https://github.com/invertase), who will maintain this extension going forward. Please see [this issue](https://github.com/stripe/stripe-firebase-extensions/issues/524) for more details. 
+Once the transfer is complete, you’ll need to uninstall the `stripe/firestore-stripe-payments` extension and install `invertase/firestore-stripe-payments` from the Firebase Extension Hub.
+
 # Stripe Firebase Extensions
 
 This repository contains the source code for Firebase Extensions that enable payment functionality. Created and tested by Stripe, these official Stripe Firebase extensions are reliable and secure. To learn more about Firebase Extensions, including how to install them in your Firebase projects, visit the [Firebase documentation](https://firebase.google.com/docs/extensions).
@@ -15,4 +19,4 @@ This repository includes the source code for the following extensions:
     - [Source code](./firestore-stripe-payments)
 1. Send invoices using Stripe
     - [Homepage](https://firebase.google.com/products/extensions/firestore-stripe-invoices)
-    - [Source code](./firestore-stripe-invoices)
+    - [Source code](./firestore-stripe-invoices)