Add comment how to build isoImage

hosts/bootstrap.nix

@@ -1,9 +1,6 @@
 { profiles, ... }:
 {
-  # build with: `nix build '.#nixosConfigurations.bootstrap.config.system.build.bootstrapIso'`
-  # reachable on the local link via ssh root@fe80::47%eno1
-  # where 'eno1' is replaced by your own machine's network
-  # interface that has the local link to the target machine
+  # build with: `nix build ".#nixosConfigurations.bootstrap.config.system.build.isoImage"`
   imports = [
     # profiles.networking
     profiles.users.root # make sure to configure ssh keys