Create documentation for configuring BounceHandler with Postfix
See https://phabricator.wikimedia.org/T114252
Note that this task is advanced because it requires you to configure a local test environment for MediaWiki and its BounceHandler extension ( https://www.mediawiki.org/wiki/MediaWiki-Vagrant could be helpful), and Postfix.
Documentation exist to use MediaWiki's bouncehandler extension with Exim at https://www.mediawiki.org/wiki/Extension:BounceHandler. Document the same for Postfix ( http://www.postfix.org/ ) in a dedicated section on https://www.mediawiki.org/wiki/Extension:BounceHandler (you can draft it on a wiki sub page under your personal user wiki page on mediawiki.org).
Steps: 1) Install the BounceHandler extension 2) Install postfix mail server, and create a bounce from Mediawiki 3) Configure postfix to HTTP POST the bounce email back to Bouncehandler API 4) Document Help - http://brianbrunner.com/automation/postfix/email/2013/09/09/postfix.html