title: Fix with ulimit -n 8192
body: <p>Running <code>caddy</code> on a linux machine, and I receive the following error: </p>
  
  <pre><code>WARNING: File descriptor limit 1024 is too low for production servers.
           At least 8192 is recommended. 
  
           Fix with "ulimit -n 8192"
  </code></pre>
  
  <p>Ok, great.  But where do I fix it? </p>