Register file associations when installing mpv.net

[soredake]

Is your feature request related to a problem? Please describe.
Right now, installer are not doing this.

Describe the solution you'd like
Registering file associations when install mpv.net.

Describe alternatives you've considered
Using built-in menu to do this in mpv.net

Additional context
Example innosetup installer that registers file associations https://github.com/nomacs/nomacs/blob/539959ec46e1ecb594aded0d0a7f58412f05b51e/installer/nomacs-setup.iss

[eastmarch]

Installed mpv.net last year and both files associations and protocol handlers like ytdl:// were registered in windows back then. Can't even recommend the app anymore to my extension users.