Some random Gentoo ebuilds
To add the repo to layman's database, to the following:
Add https://raw.github.com/ddemidov/ebuilds/master/overlay.xml to the "overlays" section of /etc/layman/layman.cfg.
Fetch the remote list of database using "layman -f"
Add the repo to layman using "layman -a ddemidov"