Provide default launchd file for mac OS X

[benjaminweb]

It's not straightforward to schedule running rustic on Mac as it requires a correctly specified launchd job (which is rather hard to debug): https://developer.apple.com/library/archive/documentation/MacOSX/Conceptual/BPSystemStartup/Chapters/ScheduledJobs.html

Having a template / example (like the systemd files) facilitates the usage of rustic on a Mac.

https://creativeprojects.github.io/resticprofile/schedules/launchd/index.html https://creativeprojects.github.io/resticprofile/schedules/index.html Restic Profile launchd plist file generator: https://github.com/creativeprojects/resticprofile/blob/master/darwin/launchd.go

[aawsome]

Thanks for opening the issue @benjaminweb!

We surely can add this to the repo - if there is anyone who is willing to create it. AFAIK the core maintainers do not use OS X, so there is no possibility from our side.

Anyone up for a PR? (We can help with technical details how to create one, if anyone is willing to work on this topic!)