Fix: README.md

Author: aopoltorzhicky

pkg/storage/README.md

@@ -57,8 +57,9 @@ type Transaction interface {
 	BulkSave(ctx context.Context, models []any) error
 	Close(ctx context.Context) error
 	HandleError(ctx context.Context, err error) error
-	Exec(ctx context.Context, query any, params ...any) (int, error)
-	CopyFrom(r io.Reader, query string, args ...any) error
+	Exec(ctx context.Context, query string, params ...any) (int64, error)
+	CopyFrom(ctx context.Context, tableName string, data []Copiable) error
+	Tx() *bun.Tx
 }
 ```