README.md in postmark-rails-0.5.1 vs README.md in postmark-rails-0.5.2

@@ -14,20 +14,22 @@
 ## Configuring your Rails application
 
 Add this to your Gemfile: (change version numbers if needed)
 
 ``` ruby
-gem 'postmark-rails', '~> 0.5.1'
+gem 'postmark-rails', '~> 0.5.2'
 ```
 
 Don’t forget to run `bundle install` command every time you change something in the Gemfile.
 
 Add this to your config/application.rb:
 
 ``` ruby
 config.action_mailer.delivery_method = :postmark
 config.action_mailer.postmark_settings = { :api_key => "your-api-key" }
 ```
+
+The `postmark_settings` hash can contain [all options](https://github.com/wildbit/postmark-gem#communicating-with-the-api) supported by `Postmark::ApiClient`.
 
 For the API details, refer to the [developer documentation](http://developer.postmarkapp.com).
 
 ## Tagging your deliveries