Rusty journal

Example of usage

cargo run -- -j test-journal.json add "buy milk"
cargo run -- -j test-journal.json add "take the dog for a walk"
cargo run -- -j test-journal.json add "water the plants"
cargo run -- -j test-journal.json list
cargo run -- -j test-journal.json done 2
cargo run -- -j test-journal.json list