README.md in rbs-1.2.1 vs README.md in rbs-1.3.0

@@ -5,10 +5,10 @@
 It also allows declaring constants and global variables.
 
 The following is a small example of RBS for a chat app.
 
 <!-- run-start:a.rbs:bundle exec rbs -I a.rbs validate -->
-```rbs
+```rb
 module ChatApp
   VERSION: String
 
   class User
     attr_reader login: String