[Feature Request] Separate sound for pre-notification

[Jaaaarne]

First of all, thank you for the app. I've been using it for over a year, and it's been very useful for fighting procrastination. It went through two NaNoWriMo events with me. :)

There are a couple of things that would be nice to have, though. I don't know how much effort it would be to implement, so feel free to disregard me if it's too much.

1. There's a setting that turns on pre-notification at the last minute of work session. It uses the finished work notification sound. Would it be possible to have a separate sound for it? Now you can only set a Start sound and an End sound.

2. Would it be possible to have a pre-notification for a break as well? It could use the same sound as work session pre-notification (so, three sounds overall: work end, break end and pre-notification).

Thank you in advance if you find it possible to implement this some time. And even if you don't, thank you anyway. :)