Add backup script

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/common/configs/user/gui/theme/theme.sh

@@ -18,8 +18,9 @@ toggle_mode() {
   fi
 }
 
-show_usage() {
+usage() {
   echo "Usage: theme [-m {light|dark|toggle}] [-w <file>]"
+  exit 1
 }
 
 finish() {
@@ -42,8 +43,7 @@ while getopts "m:w:" opt; do
           toggle_mode
           ;;
         *)
-          show_usage
-          exit 1
+          usage
           ;;
       esac
       ;;
@@ -51,8 +51,7 @@ while getopts "m:w:" opt; do
       set_wallpaper "$OPTARG"
       ;;
     *)
-      show_usage
-      exit 1
+      usage
       ;;
   esac
 done