title: RegExp match more than two empty lines
body: <p>I am using Emacs and one of its modes separates the code into groups of smaller codes if there is an empty line between lines. It uses <code>^\s-*$</code> regular expression as a matching line. However, I want to configure it to behave as separate to groups <strong>when there is 2 or more empty lines</strong> between lines. What is the regular expression for this?</p>
  <p>For example right now:</p>
  <pre><code>*Group 1 starts*
  Line1
  Line2
  *Group 1 ends*
  --empty line
  *Group 2 starts*
  Line3
  *Group 2 ends*
  --empty line
  --empty line
  *Group 3 starts*
  Line4
  Line5
  *Group 3 ends*
  </code></pre>
  <p>I want it to look like this:</p>
  <pre><code>*Group 1 starts*
  Line1
  Line2
  --empty line
  Line3
  *Group 1 ends*
  --empty line
  --empty line
  *Group 2 starts*
  Line4
  Line5
  *Group 2 ends*
  </code></pre>