README.md in catarse_paypal_express-1.0.0 vs README.md in catarse_paypal_express-2.0.0

@@ -16,9 +16,16 @@
 
 Configure the routes for your Catarse application. Add the following lines in the routes file (config/routes.rb):
 
     mount CatarsePaypalExpress::Engine => "/", :as => "catarse_paypal_express"
 
+## Rails 3.2.x and Rails 4 support
+
+If you are using the Rails 3.2.x on Catarse's code, you can use the version `1.0.0`.
+
+For Rails 4 support use the `2.0.0` version.
+
+
 ### Configurations
 
 Create this configurations into Catarse database:
 
     paypal_username, paypal_password and paypal_signature