Document more clearly the working_directory option

[duckmole]

Issue from @Pierstoval The docs about Working Directories are not clear enough to me.

In the example, does the working_directory "/tmp/backups" corresponds to the directory where the backups will be saved after executing the job in the remote server before being "pulled" to the local server in the "/var/backups" directory?

[jefmathiot]

@duckmole I guess we should provide a full blown example with a copy of file from a remote host to the localhost, then another copy from the localhost to another remote host. This way we could document the final state on each host (assuming each of them has a different working dir).

[Pierstoval]

Thanks @duckmole for bringing the issue here, and yes, a complete example of the whole workflow from a Sheepfile with working directories to the final file structures might be clear enough. Plus, it would bring a "more real" example of how Electric Sheep works :)