nixos/initrd: improve descriptions

The improved lspci command shows all available ethernet controllers and
their kernel modules. Previously, the user had to provide the slot name
of a specific device.

nixos/modules/system/boot/initrd-ssh.nix

@@ -82,6 +82,7 @@ in
       default = config.users.users.root.openssh.authorizedKeys.keys;
       description = ''
         Authorized keys for the root user on initrd.
+        Note that Dropbear doesn't support OpenSSH's Ed25519 key type.
       '';
     };