Feature: log to stdout

[rektide]

Currently, the only output is to logs. By default I got output to /home/rektide/.local/share/com.pais.handy/logs.

I thought Handy was totally not working at all. But it turned out that it just hasn't been able to get the register the push to talk hotkeys! Being able to see this more visibly would have been great. I also have Handy setup as a systemd user-service, which normally is very good about being a one-stop place to see the state of a program and it's output, but there's no output, which is not ideal.

[cjpais]

Thanks for the pointing out of this, I think it would also be good to have more standard logging practice on Linux. If you want to take this up it'd be much appreciated as a PR.