Refreshed and face-lifted README.  Tested with Chaos Calmer.  Worked wit...

This is the pull request I said I'd make earlier today.
Does it need to be?  No, of course not.  At the end of the day, though, this is a fairly substantial vector for people who haven't, or have only rarely, run make.  It's quite plausible that they might get permission denied errors and try to sudo.  If they do, they'll be in a pretty bad permissions situation.  So why not gently remind them in one line.  There's no prompt before it; they aren't going to mistake it for code (similar to the menu selection description).  It's fine.