Update help message - Minor update

Minor update: Updated help message

~$ setcustomres -help
Description: Set custom resolution to a display using xrandr
Usage: setcustomres [OPTIONS]...
Version: 2.2.1

-w | -width <integer>            Mandatory: Width of resolution
-h | -height <integer>           Mandatory: Hight of resolution
-o | -output <string>            Mandatory: Display output
-r | -refresh-rate <integer>     Custom refresh rate (Default 60Hz)
-p | -param "<string>"           Xrandr parameters - Wrap with double quotes
-u | -update <path>              Standalone: Update setcustomres (requires path to setcutomres local repository)
-v | -version                    Standalone: Print version
-help                            Standalone: Print this help message