add ruby and javascript refactoring support

ruby-refactor and js2-refactor are good refactoring plugins out there for emacs. Through 'emr-declare-command' given by emacs-refactoring, I have extended support for ruby-refactor and js2-refactor.
use proper subheading for ruby and javascript under langauge support in README
Merge pull request #2 from tacticiankerala/master

Update readme to mention ruby and js support