Setting fade-in length

[LienRag]

Checklist

• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the request will be dismissed otherwise.
• This issue contains only one feature request.
• I have read and understood the contribution guidelines.

Feature description

Fossify Clock has a toggle "augmenter progressivement le volume" but it is not configurable.
Please add parameters to that option, like duration and starting volume.

Why do you want this feature?

Humans sleep in cycles, usually 45-minutes long.
Awaking while being between sleep cycles is way preferable than while inside a sleep cycle.

Fade-in beginning with a very low volume allows to wake up only when the sleep cycle is finished (the Fake Dawn application does that very well; alas it very often doesn't trigger, making it completely unreliable as an alarm).

Since in many cases, external constraints force one to wake up not later than HH:MM it is useful to have this fade-in configurable, so one could still hope to wake up nicely when the sleep cycle ends, while having a fixed limit where the volume will be loud enough to wake them up even if they are deep into their sleep cycle.

Additional information

To make full use of this, you may want to add some soft ringtones to your default lists (I used soft music for FakeDawn).