Add command line option to disable audio

[ndren]

I'm running into something like RustAudio/cpal#695 or RustAudio/cpal#634, preventing me from playing audio on any other application once speki is running. If/when RustAudio/cpal#692 gets merged, that should work fine too.

Until upstream fixes this, I think it would be easiest to allow a flag to disable sound at runtime, maybe --no-audio. This must disable audio code entirely, not mute it, to deal with this bug.

[TBS1996]

Thanks for notifying me of this! I'll get into setting up CLAP eventually, but for now I added the ability to mute/unmute with Alt+m, it's available in the newest version 0.1.10.

let me know if it fixes your audio problems!

[ndren]

I've tried the new binary from the README and muting speki does fix the issue, thanks!