README.md in growthforecast-client-0.80.1 vs README.md in growthforecast-client-0.80.2

@@ -34,9 +34,20 @@
 
 ```
 $ growthforecast-client help
 ```
 
+### Tips
+
+#### Debug Print
+
+Following codes prints the http requests and responses to STDOUT
+
+```
+client = GrowthForecast::Client.new('http://localhost:5125')
+client.debug_dev = STDOUT # IO object
+```
+
 ## Contributing
 
 1. Fork it
 2. Create your feature branch (`git checkout -b my-new-feature`)
 3. Commit your changes (`git commit -am 'Add some feature'`)