Fixed printed help

src/light.c

 static void _light_print_usage()
 {
     printf("Usage:\n"
-        "  light [OPTIONS] <COMMAND> [VALUE]\n"
+        "  light [OPTIONS] [VALUE]\n"
         "\n"
         "Commands:\n"
         "  -H, -h      Show this help and exit\n"
         "  -V          Show program version and exit\n"
         "  -L          List available devices\n"
         
-        "  -A <value>  Increase brightness by value\n"
-        "  -U <value>  Decrease brightness by value\n" 
-        "  -S <value>  Set brightness to value\n"
+        "  -A          Increase brightness by value\n"
+        "  -U          Decrease brightness by value\n" 
+        "  -S          Set brightness to value\n"
         "  -G          Get brightness\n"
-        "  -N <value>  Set minimum brightness to value\n"
+        "  -N          Set minimum brightness to value\n"
         "  -P          Get minimum brightness\n"
         "  -I          Save the current brightness\n"
         "  -O          Restore the previously saved brightness\n"
         "\n"
         "Options:\n"
         "  -r          Interpret input and output values in raw mode\n"
-        "  -s <value>  Specify device target path to use, use -L to list available\n"
-        "  -v <value>  Specify the verbosity level (default 0)\n"
+        "  -s          Specify device target path to use, use -L to list available\n"
+        "  -v          Specify the verbosity level (default 0)\n"
         "                 0: Values only\n"
         "                 1: Values, Errors.\n"
         "                 2: Values, Errors, Warnings.\n"