Use kanshi for display management in sway

As long as kanshi is running it should automatically manage displays
based on the definitions in its config.

kanshi/config

@@ -0,0 +1,18 @@
+{
+    output eDP-1 scale 2 mode 2560x1440 position 0,0
+    output HDMI-A-1 scale 1 mode 1280x720 position 1280,0
+}
+
+{
+    output eDP-1 scale 2 mode 2560x1440 position 0,0
+}
+
+{
+    output eDP-1 disable
+    output DP-3 scale 2 mode 2560x1440 position 0,0
+}
+
+{
+    output eDP-1 disable
+    output DP-4 scale 2 mode 2560x1440 position 0,0
+}

sway/config

@@ -43,35 +43,8 @@ output * bg /usr/share/backgrounds/sway/Sway_Wallpaper_Blue_1920x1080.png fill
 #
 # You can get the names of your outputs by running: swaymsg -t get_outputs
 
-# eDP-1 is the internal laptop display
-output eDP-1 {
-    scale 2
-    resolution 2560x1440
-    position 0,0
-}
-
-# DP-3 and DP-4 are display port when connected to dock
-output DP-3 {
-    scale 2
-    resolution 2560x1440
-    position 1280,0
-}
-
-output DP-4 {
-    scale 2
-    resolution 2560x1440
-    position 1280,0
-}
-
-output HDMI-A-1 {
-    scale 1
-    resolution 1280x720
-    position 1280,0
-}
-
-set $laptop eDP-1
-bindswitch --reload lid:on output $laptop disable
-bindswitch --reload lid:off output $laptop enable
+# Automatic display management
+exec kanshi
 
 # Wayland overlay bar for sound and brightness level
 exec mkfifo $SWAYSOCK.wob && tail -f $SWAYSOCK.wob | wob