Volume Control

[chall8908]

This is probably the biggest missing feature for me. I did some poking around at the SpotifyAPI-NET library and it looks like a simple volume slider should be doable.

The current volume is contained in the Device class which is returned as part of the Currently Playing Context response (Spotify API Docs). It can be set via the setVolume function of the PlayerClient.

I would try my hand at a PR, but I've had very little luck figuring out how to get into making mods for 14.