Say "quit application" instead of "close application"

[bertfrees]

Nitpick for more consistency: change the phrasing for the "Action on closing the app window" setting. It would be better to say "quit application" instead of "close application" as this is more consistent with how it is called elsewhere (at least on macOS).

Choose here if you want to keep the application running in the tray or quit it when closing the app window.

Quit the application

[marisademeglio]

Check in with wording again after #129

[marisademeglio]

I think we can close this issue now, what do you think @NPavie @bertfrees ?

[bertfrees]

Yes, looks fine now!