The Arch Wiki on keyboard layouts set to edit this file to change the keyboard layout:

/etc/X11/xorg.conf.d/00-keyboard.conf

These are the contents of this file:

# Written by systemd-localed(8), read by systemd-localed and Xorg. It's # probably wise not to edit this file manually. Use localectl(1) to # instruct systemd-localed to update it. Section "InputClass" Identifier "system-keyboard" MatchIsKeyboard "on" Option "XkbLayout" "us,us" Option "XkbModel" "pc104" Option "XkbVariant" "qwerty,colemak" Option "XkbOptions" "grp:shift_caps_toggle" EndSection 

What I want it to do is set the default layout to qwerty, and an alternative layout colemak. To switch between layout, I want to press shift and capslock. This does not work. Pressing shift and capslock does not switch to colemak.