- Switch from a single additional thread (receiving/holding a single `Arc::clone` reference) running a loop modeling 10 sequential jobs, to a loop generating 10 threads each modeling 1 job (each getting their own `Arc::clone` reference)
- use the previously ignored `for` loop var to keep the execution timing approx the same
- Print a more descriptive waiting message (taking an opportunity to use comment to disambiguate the count)
Hints are now accessible using the CLI subcommand `rustlings hint
<exercise name`.
BREAKING CHANGE: This fundamentally changes the way people interact with exercises.