Update README.md

Added link buttons-rails
Merge pull request #1 from rajahafify/master

I have written a wrapper for ruby friendly version. I hope you can mention in your page :)
updated readme
added original colors to commented color options
Updated buttons docs. Renamed button.css buttons.css
Updated download
Merge branch 'master' of https://github.com/alexwolfe/Buttons into gh-pages
Merge branch 'gh-pages' of https://github.com/alexwolfe/Buttons into gh-pages