Allows one to call a script whenever the monitor configuration changes
(connect/disconnect). As an example, one might want to update the
wallpapers on each display. Here is a script that could be called by
`monchange` in the `config.h` to achieve this:
```
wallDir="${XDG_CONFIG_HOME:-$HOME}/wallpapers"
displays="$(wlr-randr --json | jq -r '.[] | select(.enabled) | .name')"
echo "$displays"
setDisplay() {
case $(ls $wallDir) in
*"$1"*)
wall=$(ls $wallDir | grep "$1" | head -n 1)
;;
*)
wall=$(ls $wallDir | grep "default" | head -n 1)
;;
esac
swaybg --output $1 -m fill --image $wallDir/$wall &
}
killall swaybg > /dev/null 2>&1
for display in $displays; do
setDisplay $display
done
```
