-YARD - A Ruby Documentation Tool
--http://yardoc.org/
-File: Getting Started Guide - Documentation for yard
--http://www.rubydoc.info/gems/yard/file/docs/GettingStarted.md
-YARD,RDoc 比較 - Qiita
--http://qiita.com/kmats@github/items/0c8919a65afbe18e9e37