Allow configure (some) config options via environment or allow using password / token files

[viceice]

Currently you need to store the token / password in the config file, which makes the full file confidential.
It should be possible to allow configuring at lease the password / token via environment.

Alternatively it would be also possible to use password / token files, so you can use docker secrets so securly pass the token / password.

On kubernetes this would allow mounting secrets as files too.

[TheArcaneBrony]

This is implemented in Draupnir if you want to take reference from that, and is also actively used in the NixOS module for that.