Add Asunder

[werdahias]

Asunder is a CD ripping tool for the GTK desktop. It's written in GTK2, but there is a GTK3 fork available:

https://gitlab.gnome.org/Salamandar/asunder

[Kazhnuz]

Sorry for answering so late : I think we shouldn't add new GTK3 apps to the list, as even if it's still supported, it's clearly in the "oldstable" category and replaced by GTK4+libadwaita.