Simple rust project structure for Advent of Code.

There's nothing fancy going on here. I was just going through 2022 and realized it would be easy to hand make a template to save some of the boiler plate setup for each day.

Each day:

1. copy your input in to input/day{x}.txt
2. Edit day{x}.rs:
   1. Set INPUT to be the sample input.
   2. Update the assert_eq! lines to match the example provided
   3. Implement the day{x}_part1 and day{x}_part2 functions
3. cargo test to run your tests with the example input
4. cargo run to run with your input