Timer for the new auto-mute feature

[nykula]

Hello! Muting the media volume automatically is a nice addition. It can be more useful with a configurable delay, e.g. for a duration of an average YouTube video, a song or an Instagram short. I see the UI as a number input or a select: 15 minutes (default?), 5 minutes and 1 minute; 0 to completely turn off the sound like it works now. Similar to how there are apps on F-Droid to turn off Wi-Fi automatically after a period of not using it (they're all for older Android versions though, something might be preventing them from working now). Is such a feature possible to implement in Mute

[mueller-ma]

PRs are welcomed :)