Allow arbitrary command as notification option on changes

[anaynayak]

Thanks for building viddy! Love the improvements over watch .

I'm currently using the system bell --bell option to get notified whenever there are changes in the output of my command. However this requires one to keep a close watch on any audio notifications.

If viddy allows arbitrary commands to be run for notifications, I can then add a osascript notification that shows up on the desktop

e.g. viddy -d -b -n 20 ls --notify-command ./notify.sh

and notify.sh could contain something like:
osascript -e 'display notification "hello world!"'

Alternatively, direct integration with tools like https://github.com/gen2brain/beeep which will provide cross platform desktop notifications directly. I'm guessing this option will be less preferably since people might want to use viddy on non-desktop environments.