wayland: Set up basic multi-display support

Added continuous wallpaper setting and different settings for laptop use
(only one screen enabled) and docked use (two screens enabled and laptop
screen disabled) using the wonderful `kanshi` program.

wayland/.config/kanshi/config

@@ -0,0 +1,9 @@
+profile docked {
+    output eDP-1 disable
+    output "Goldstar Company Ltd W2442 0x000075FD" position 1920,0
+    output "Goldstar Company Ltd W2442 0x000075E1" position 0,0
+}
+
+profile single {
+    output eDP-1 enable position 0,0
+}

wayland/.config/river/init

@@ -224,12 +224,25 @@ for pad in $(riverctl list-inputs | grep -i touchscreen); do
 done
 
 setxkbmap -option "compose:menu"
-exec swaybg -i ~/pictures/wall.jpg -o '*' -m fill &
+# set a nice wallpaper
+exec swww init &
+if [ -e "$HOME/pictures/wall_l.jpg" ] && [ -e "$HOME/pictures/wall_r.jpg" ]; then
+    swww img -o DP-5 "$HOME/pictures/wall_l.jpg" &
+    swww img -o DP-3 "$HOME/pictures/wall_r.jpg" &
+elif [ -e "$HOME/pictures/wall.jpg" ]; then
+    swww img "$HOME/pictures/wall.jpg" &
+fi
+
 # killall mako
 # mako &
+
+# start status bar
 killall waybar
 exec waybar &
 
+# start dynamic display configuration
+exec kanshi &
+
 killall clipman
 exec wl-paste -t text --watch clipman store &
 # bash ~/.config/bin/gtktheme # setting our gtk variables