title: Laravel customize log formatter
body: <p>I want to <strong>customize the log line format</strong> of <strong>only</strong> the <strong>errorlog channel</strong>.
  Is it possible to define it in the config file (config/logging.php), or i have to made a class for it as the <a href="https://laravel.com/docs/5.6/logging#advanced-monolog-channel-customization" rel="nofollow noreferrer">doc</a> says? But it shows me no hint..</p>
  
  <p>Can somebody show me some example?</p>
  
  <p>Many thanks in advance!</p>