nixos/README: tweaks paths
nixos/README: tweaks paths

phunehehe/microgram,zalora/microgram,zalora/microgram,phunehehe/microgram,zalora/microgram,phunehehe/microgram,4z3/microgram,phunehehe/microgram,4z3/microgram,4z3/microgram,4z3/microgram,zalora/microgram