The setup script creates a new Rust binary application and downloads
the input for the day into a file called input.txt.
The script expects 2 arguments: the day, and the session cookie:
./script <day-number> <cookie>
I like to create a .cookie file (added to .gitignore) containing the
cookie's value, so I can do something like this:
cat .cookie | xargs ./setup 1
The script was adapted from @burntsushi's set-up script from AOC 2018.
The solutions are written in Rust. The solutions can be
run by executing cargo run in the day's folder.