Converts English lettering to Kana.
```rust use to_kana::{ hira, // Hiragana kata, // Katakana };
// は is pronounced "wa" in this context, but is usually pronounced "ha" let hello = hira("konnichiha").unwrap(); // こんにちは let world = kata("wa-rudo").unwrap(); // ワールド
println!("{}{}", hello, world); ```