feat: update to firebase v9 syntax in docs and fix link

Author: cabljac

README.md

@@ -4,7 +4,7 @@ It is now recommended to uninstall the `stripe/firestore-stripe-payments` extens
 
 Alternatively, you can also use the following link to convert your current installation to the Invertase version
 
-`https://console.firebase.google.com/project/_/extensions/install?instanceId=STRIPE_EXTENSION_INSTANCE_ID&ref=invertase%2Ffirestore-stripe-payments@0.3.5`
+`https://console.firebase.google.com/project/_/extensions/install?instanceId=STRIPE_EXTENSION_INSTANCE_ID&ref=invertase%2Ffirestore-stripe-payments@0.3.12`
 
 # Stripe Firebase Extensions
 

firestore-stripe-payments/CHANGELOG.md

@@ -1,3 +1,9 @@
+## Version 0.3.12 - 2025-05-06
+
+[docs] - update firebase snippets to v9 syntax
+
+[docs] - update migration link to 3.12
+
 ## Version 0.3.11 - 2025-05-24
 
 [chore] - improve tests and CI