Use multiple logs in Rust training course text
Counterpart to https://github.com/pingcap/talent-plan/issues/71
Here's an explanation from @sticnarf about why to use multiple logs https://github.com/pingcap/talent-plan/pull/120#issuecomment-491276126
It's subtle. Not sure how to present this. @sticnarf suggests we can just say to use multiple log files.
I'm thinking if we find appropriate readings for this project that describe another system with multiple log files then the student will be inclined to use a multiple-log solution.
Could also spec to use multiple logs, while linking to external explanation.
Some questions about the log format from #rust-training: https://tikv-wg.slack.com/archives/CKD9363A8/p1562670547042200