docs(nix): note detached devenv up for non-interactive use

Author: JakobLichterfeld

nix/flake-modules/devenv.nix

@@ -84,7 +84,7 @@
           port = process_compose_port;
           # The TUI keeps `devenv up` in the foreground. To run the services
           # non-interactively, start them detached
-          # with `devenv up -d` and stop them via `devenv processes stop`.
+          # with `devenv up --detached` and stop them via `devenv processes stop`.
           tui.enable = true;
         };
         services.postgres = {