Update read me

Author: hgl

README.md

@@ -202,6 +202,8 @@ We’ll do the following:
 1. Define a Home Manager user and have it use a custom module.
 1. Install NixOS with this configuration to all machines in parallel.
 
+You might expect these steps to take a long time, but as you’ll see, Nixverse can significantly speed up the process.
+
 We first define the two groups:
 
 ```nix