added some beginning docu

flake-module.nix

@@ -1,6 +1,9 @@
 {inputs, ...}:
 {
-  debug = true;
+  # debug = true;
+  # We only define machines config in this flake yet, so we only include
+  # the module that builds these. This file might get fuller, if we need to
+  # build our own packages, that are not flakes.
   imports = [ ./nixos/flake-module.nix
         # To import a flake module
         # 1. Add foo to inputs