example/init: Replace light with brightnessctl

Change screen backlight brightness command to brightnessctl(1) as
light(1) repo has been deleted.

Author: novakne

example/init

@@ -137,9 +137,9 @@ do
     riverctl map $mode None XF86AudioPrev  spawn 'playerctl previous'
     riverctl map $mode None XF86AudioNext  spawn 'playerctl next'
 
-    # Control screen backlight brightness with light (https://github.com/haikarainen/light)
-    riverctl map $mode None XF86MonBrightnessUp   spawn 'light -A 5'
-    riverctl map $mode None XF86MonBrightnessDown spawn 'light -U 5'
+    # Control screen backlight brightness with brightnessctl (https://github.com/Hummer12007/brightnessctl)
+    riverctl map $mode None XF86MonBrightnessUp   spawn 'brightnessctl set +5%'
+    riverctl map $mode None XF86MonBrightnessDown spawn 'brightnessctl set 5%-'
 done
 
 # Set background and border color