docs: Fix link to SMS API

Author: SMadani

README.md

@@ -30,7 +30,7 @@ need a Vonage account. You'll need to have [created a Vonage account](https://da
 - [Number Management](https://developer.vonage.com/en/numbers/overview)
 - [Proactive Connect](https://developer.vonage.com/en/proactive-connect/overview)
 - [Redact](https://developer.vonage.com/en/redact/overview)
-- [SMS](https://developer.vonage.com/en/sms/overview)
+- [SMS](https://developer.vonage.com/en/messaging/sms/overview)
 - [Subaccounts](https://developer.vonage.com/en/account/subaccounts/overview)
 - [Verify](https://developer.vonage.com/en/verify/overview)
 - [Video](https://developer.vonage.com/en/video/overview)