Update doc/manual/src/design/overview.md
Update doc/manual/src/design/overview.md

Co-authored-by: Valentin Gagarin <c032d54725b22060679a2623d478ec2966de1fcd@fricklerhandwerk.de>
NixOS/nix,NixOS/nix,NixOS/nix,NixOS/nix,NixOS/nix