Configuration entry similar to;
```nix
programs.pianobar = {
enable = true;
user = "groovy-tunes@example.com";
password_command = "cat /run/secrets/pianobar/groovy-tunes";
};
```
... will produce a `~/.config/pianobar/config` file with content of;
```conf
user = groovy-tunes@example.com
password_command = cat /run/secrets/pianobar/groovy-tunes
```
... and add `pianobar` to `home.packages` list.
All configurations that `man pianobar` documents _should_ available via
`extraOptions` attribute.
License, according to `NixOS/nixpkgs` is MIT, and that seems to match
what's shown on `PromyLOPh/pianobar` repo too;
- d92bfd5feb/pkgs/by-name/pi/pianobar/package.nix (L42o)
- https://github.com/PromyLOPh/pianobar/?tab=License-1-ov-file#readme
