Add Spotifyd to App Store

[lucvanloon]

Please leave feedback if I followed contribution guideline correctly. App screenshot requirement doesn't work here as this app has no UI.

[lucvanloon]

Spotifyd actually requires a spotifyd.conf file to be created. I left this instruction in the description of the app. Maybe we can automatically create that for the user but it still needs to be configured for at minimum:

1. spotify username
2. spotify password
3. audio device (likely to be: 'hw' on Raspberry Pi's at least)

[CorrectRoadH]

@raller1028

[raller1028]

@lucvanloon Hi, due to the import validation of this application involves a lot of parameters(sign up spotifyd, audio device setting ), so I can not respond to your pr quickly.