title: Increase / Decrease code font size keyboard shortcut
body: <p>I know how to change the setting : 
  <a href="https://stackoverflow.com/a/11129039/390330">https://stackoverflow.com/a/11129039/390330</a></p>
  
  <p>But I want a more live solution like I get with the mouse: <strong><em><kbd>Ctrl</kbd>+<kbd>Mouse Wheel</kbd></em></strong> shortcut. Except I need it to be a keyboard shortcut (e.g in browsers there is <kbd>Ctrl</kbd> + <kbd>+</kbd> / <kbd>Ctrl</kbd> + <kbd>-</kbd>). Is there such a keystroke / or can one be set </p>