[Feature request] Add a config file

[Benjamin ABEL]

Hi, and first thanks for this really nice piece of software. I'm using a lot audio-recorder from scripts, and I think it could be nice to add a way to load config at startup without manually editing the fields in the gui.

The config file could be stored in `~.config/audio-recorder`, and a cli option would allow to specify another location like this:

    audio-recorder --config myconfig -c start