docs: fix kms link in readme
Fixes
@@ -49,7 +49,7 @@ Google API | Status | Package
[IAM][cloud-iam] | stable | [`cloud.google.com/go/iam`](https://godoc.org/cloud.google.com/go/iam)
[IoT][cloud-iot] | stable | [`cloud.google.com/go/iot/apiv1`](https://godoc.org/cloud.google.com/go/iot/apiv1)
[IRM][cloud-irm] | alpha | [`cloud.google.com/go/irm/apiv1alpha2`](https://godoc.org/cloud.google.com/go/irm/apiv1alpha2)
-[KMS][cloud-kms] | stable | [`cloud.google.com/go/kms`](https://godoc.org/cloud.google.com/go/kms)
+[KMS][cloud-kms] | stable | [`cloud.google.com/go/kms/apiv1`](https://godoc.org/cloud.google.com/go/kms/apiv1)
[Natural Language][cloud-natural-language] | stable | [`cloud.google.com/go/language/apiv1`](https://godoc.org/cloud.google.com/go/language/apiv1)
[Logging][cloud-logging] | stable | [`cloud.google.com/go/logging`](https://godoc.org/cloud.google.com/go/logging)
[Memorystore][cloud-memorystore] | alpha | [`cloud.google.com/go/redis/apiv1`](https://godoc.org/cloud.google.com/go/redis/apiv1)
