README.md in omniauth-zalo-0.1.3 vs README.md in omniauth-zalo-0.1.4

@@ -19,9 +19,16 @@
 Or install it yourself as:
 
     $ gem install omniauth-zalo
 
 ## Usage
+omniauth.rb
+
+```
+Rails.application.config.middleware.use OmniAuth::Builder do
+  provider :zalo, ENV['APP_ID'], env['SERECT_ID']
+end
+```
 
 TODO: Write usage instructions here
 
 ## Development