Add elm2nix and stack2nix
Add elm2nix and stack2nix

soenkehahn/stackage,athanclark/stackage,massysett/stackage,iand675/stackage,spencerjanssen/stackage,simonmichael/stackage,michalkonecny/stackage,clinty/stackage,ethercrow/stackage,mstksg/stackage,stackbuilders/stackage,asr/stackage,Daniel-Diaz/stackage,mrkkrp/stackage,int-index/stackage,peti/stackage,fimad/stackage,fpco/stackage,wereHamster/stackage,jonschoning/stackage