[Tutorial-Coding] Play a notification sound in Synfig / Add a toggle in preferences

sound
notification
preferences

#1

For the devs, after adding Render Done sound to the code, I added some reference in the Wiki.
It can be used as well to implement a toggle in the Preferences.
https://wiki.synfig.org/Dev:Adding_a_Sound_notification
Cheers :slight_smile: