Strafe button missing

[dem1980]

Hi,
in mapping menu (PORT 1 CONTROLS), we have the buttons :

• strafe left
• strafe right
• strafe +
• strafe -
  But there is not a strafe button. It is a button we have to maintain with a direction to strafe in this direction.
  For example, if i maintain the strafe button and i go left, the guy have to strafe left.
  In PrDoom we have this button for example so it could be possible in RetroArch and in this port too.
  Thank you