doc: adds brendanashworth as collaborator

Moment of truth?

PR-URL: https://github.com/iojs/io.js/pull/587


Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>
Reviewed-By: Rod Vagg <rod@vagg.org>
Reviewed-By: Brendan Ashworth <brendan.ashworth@me.com>