doc: change the info to the same as in gitconfig

PR-URL: https://github.com/nodejs/io.js/pull/2000


Reviewed-By: Yosuke Furukawa <yosuke.furukawa@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Johan Bergström <bugs@bergstroem.nu>