README.md in tel_formatter-0.0.1 vs README.md in tel_formatter-0.0.2

@@ -24,9 +24,11 @@
     $ gem install tel_formatter
 
 ## Usage
 
 ```ruby
+require 'tel_formatter'
+
 Telformatter.format("0312345678") #=> "03-1234-5678"
 Telformatter.format("０３．１２３５．５６７８") #=> "03-1234-5678"
 ```
 
 ## Contributing