doc(storage): reference storage control in pkg doc (googleapis#9692)

Add reference to storage control docs so that people who are looking for Folders/Managed Folders features know where to find these APIs.

Also correct a typo in the direct path docs

storage/doc.go

@@ -350,7 +350,7 @@ To create a client which will use gRPC, use the alternate constructor:
 	// Use client as usual.
 
 If the application is running within GCP, users may get better performance by
-enabling Google Direct Access (enabling requests to skip some proxy steps). To enable,
+enabling Direct Google Access (enabling requests to skip some proxy steps). To enable,
 set the environment variable `GOOGLE_CLOUD_ENABLE_DIRECT_PATH_XDS=true` and add
 the following side-effect imports to your application:
 
@@ -359,6 +359,13 @@ the following side-effect imports to your application:
 		_ "google.golang.org/grpc/xds/googledirectpath"
 	)
 
+# Storage Control API
+
+Certain control plane and long-running operations for Cloud Storage (including Folder
+and Managed Folder operations) are supported via the autogenerated Storage Control
+client, which is available as a subpackage in this module. See package docs at
+[cloud.google.com/go/storage/control/apiv2] or reference the [Storage Control API] docs.
+
 [Cloud Storage IAM docs]: https://cloud.google.com/storage/docs/access-control/iam
 [XML POST Object docs]: https://cloud.google.com/storage/docs/xml-api/post-object
 [Cloud Storage retry docs]: https://cloud.google.com/storage/docs/retry-strategy
@@ -367,5 +374,6 @@ the following side-effect imports to your application:
 [impersonation enabled]: https://cloud.google.com/sdk/gcloud/reference#--impersonate-service-account
 [IAM Service Account Credentials API]: https://console.developers.google.com/apis/api/iamcredentials.googleapis.com/overview
 [custom audit logging]: https://cloud.google.com/storage/docs/audit-logging#add-custom-metadata
+[Storage Control API]: https://cloud.google.com/storage/docs/reference/rpc/google.storage.control.v2
 */
 package storage // import "cloud.google.com/go/storage"