That would be nice, but unfortunately I'm not a Gentoo maintainer so I can't directly add it myself, now it's possible to submit ebuilds to the main repo but I'm not familiar with how exactly that would work, it's possible, but I haven't done it before, so I think it would be way more involved since I'd have to submit a new ebuild every time I want to update it instead of just being able to push to my own repo. Also since I submitted my repo to the gentoo repositories list you can add it directly via eselect repository and the package shows up on sites like GPO (see: http://gpo.zugaina.org/games-rpg/thedarkmod) so anyone who searches that will be able to find it and install it without too much trouble, since a lot of people already use overlays.
I'll look into it though.