Add a swaybg backend?

[akumar-xyz]

I believe there are no supported backends for wayland compositors.

Something like:

#!/bin/sh

# Terminate already running swaybg instances
killall -q swaybg

# Wait until the processes have been shut down
while pgrep -u $UID -x  swaybg >/dev/null; do sleep 1; done

# Set new bg
swaybg -i "$1" &

should work fine

Would have directly submitted a pull request if I were still using github.. apologies 😅