title: This expression should have type 'unit', but has type 'ConsoleKeyInfo'
body: <p>I just wanted to pause in an F# console application, so I wrote:</p>
  
  <p>Console.ReadKey()</p>
  
  <p>But this gives the warning: <code>This expression should have type 'unit', but has type 'ConsoleKeyInfo'.</code></p>
  
  <p>What can I do to fix this?</p>