Update pkgs/record_use/README.md

Co-authored-by: Devon Carew <devoncarew@google.com>

pkgs/record_use/README.md

@@ -19,6 +19,7 @@ any constant instance of the class will be recorded. This is particularly useful
 when using the class as an annotation.
 
 ## Example
+
 ```dart
 import 'package:meta/meta.dart' show RecordUse;