Add "The Unarchiver"

[jeffpak]

http://unarchiver.c3.cx/unarchiver

Necessary to unarchive the VMs provided by Microsoft (https://developer.microsoft.com/en-us/microsoft-edge/tools/vms/mac/)

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this. You can view the current status of your issue at: https://www.pivotaltracker.com/story/show/118865129.