Add command line support

[Muhammadhussein Ammari]

Please add command line support, for example:

• WinDynamicDesktop.exe --refresh -> Refresh wallpaper
• WinDynamicDesktop.exe --theme=auto -> Set auto theme
• WinDynamicDesktop.exe --theme=light -> Set light theme
• WinDynamicDesktop.exe --theme=dark -> Set dark theme

[Timothy Johnson]

Added support for the following commands in 73bf93a:

• WinDynamicDesktop.exe /refresh
• WinDynamicDesktop.exe /theme:auto
• WinDynamicDesktop.exe /theme:light
• WinDynamicDesktop.exe /theme:dark

You can download a test build from GitHub Actions here. Are there any other commands that would be helpful to have?

[Salman Anwer]

Works beautifully! Thank you!