This is my new Portage tree overlay.
You can add it with eselect repository:
eselect repository add getburning git https://github.com/GetBurning/getburning-overlayOr with a configuration file in /etc/portage/repos.conf/:
[getburning]
location = /var/db/repos/getburning
sync-type = git
sync-uri = https://github.com/GetBurning/getburning-overlay
Or just copy things to your own overlay.