sway: structure scripts, add helpers in separate file

bin/brightness

@@ -1,5 +1,11 @@
 #!/bin/bash
+source $HOME/.config/sway/bin/helpers
 DEVICE=sysfs/backlight/intel_backlight
+APP=light
+
+## main
+_log BRIGHTNESS INFO args: $*
+_check_app $APP
 
 case $1 in
   d*)
@@ -9,6 +15,7 @@ case $1 in
     light -s $DEVICE -A 10
     ;;
   *)
-    echo "ERROR: invalid command: \"$1\""
+    echo "invalid argument: \"$1\""
+    echo "arguments: [decrease|increase]"
     ;;
 esac