Fix flickering KDE Plasma display

My Plasma display flickers wildly between black and non-black whenever switching focus or other random interactions with the GUI, it has done this from time to time, but has recently gotten worse.

From https://bbs.archlinux.org/viewtopic.php?pid=1595276#p1595276

Create a file named 20-intel.conf on /etc/X11/xorg.conf.d with the following contents:

Section "Device"
   Identifier  "Intel Graphics"
   Driver      "intel"
   #Option      "AccelMethod"  "sna"
   Option      "TearFree"    "true" 
   Option      "DRI"    "3"