Function affine_encrypt

Encrypts a message using the affine cipher. # Arguments `key` - The encryption key (encoded as key_a * SYMBOLS.len() + key_b) `message` - The plaintext message to encrypt # Returns `Ok(String)` with the encrypted message, or `Err(String)` if keys are invalid # Example ``` use the_algorithms_rust::ciphers::affine_encrypt; let encrypted = affine_encrypt(4545, "The affine cipher is a type of m

(key: usize, message: &str)