add instructions to install a systemd service

[anarcat]

I have removed the --verbose option which I tested here because it
doesn't do anything, see #11.

Otherwise this is pretty much what I'm using in production now.

Closes: #10

[gares]

Thanks very much for this!

I've just one little question, I'm no systemd expert.
I've the impression that the one shot service depends on networking being no, while the timer one does not declare such a need. Is it a limitation of systemd or it can be actually expressed? (I mean "run this every X if Y holds")

[anarcat]

I've the impression that the one shot service depends on networking being no, while the timer one does not declare such a need. Is it a limitation of systemd or it can be actually expressed? (I mean "run this every X if Y holds")

As we discussed in #10, the network-online.target doesn't actually trigger in user environment, unfortunately. It's purely cosmetic, and somewhat wishful thinking that it would eventually work. We might want to simply remove it.

But that said, I believe it's sufficient to have it in the .service file.

[gares]

Oh right, I did forget. Thanks again