Add an example journal-brief@.service file

[adrianheine]

The paths are according to the Debian package, if you actually want to include this, I can adapt them.

Another issue is that the cursor file has to exist for this to work. Maybe we don't want to be so strict about the cursor file.

[bbx0]

For the AUR package I added these service units in combination with an adjusted default configuration. When no cursor file exists, the scope is limited to the current boot as a fallback. (The StateDirectory is read-write by default, and it handles other things like Requisite.)

• journal-brief.service
• journal-brief.timer
• journal-brief.yaml

I don't think a template service should be used as journal-brief handles complex configurations with one file already.