Make binding a configurable option and the Spotify URL point to the actual URL

[manzanit0]

Hi!

The PR is fairly small, so it might be quicker to skip through the code, but it basically:

• Allows users to configure the binding through an option such as: set -g @spotifybinding 'S' in their .tmux.conf.
• Has the Copy URL command actually return the song's URL instead of its ID.

I hope it helps!

[frm]

+1 on this, the configurable binding is huge plus

[rawnly]

@xamut nothing on this?