New package: branding MATE the right way. Because we can!

	new file:   x11-themes/kogaion-artwork-mate/Manifest
	new file:   x11-themes/kogaion-artwork-mate/files/org.mate.kogaion.gschema.override
	new file:   x11-themes/kogaion-artwork-mate/kogaion-artwork-mate-1.0.ebuild