Click the Downloads link (top right) and download a ZIP or TGZ file with all of the files in this repository. Load what you like.
If you'd like to write your own Cortana scripts, take a look at the Cortana Tutorial. This tutorial also explains how to connect Cortana bots to a collaboration server.
If you'd like to contribute, fork this repository, make your modifications, and submit a pull request. Each script should have its own folder with a .cna file, any resources, and optionally a readme.
Optionally, if you're not a git warrior, you may email your script contribution to contact at fastandeasyhacking dot com.
If you have a scripting question, ask it on the Cortana Hackers mailing list. To subscribe, simply send a message to firstname.lastname@example.org. The librelist.com server will discard the first message you send and subscribe you to the list. Send an email to email@example.com to unsubscribe.
If you'd like to chat in real-time, please join #armitage on irc.freenode.net. The folks in the channel aren't active all the time. You may need to ask your question and wait for a response.
If you find a bug in a script, contact its author. If you find a bug in Cortana or have a feature request, file it in the Armitage Issue Tracker