Function decrypt 

pub fn decrypt(
    input: &str,
    output: &str,
    password: &str,
    keys: &[String],
) -> Result<(), Box<dyn Error>>

Decrypt all (or a filtered subset of) vault-encrypted values in a JSON or YAML file.

• input: path to the input file
• output: path to write the result, or "stdout" to print to stdout
• password: vault password
• keys: dot-notation key paths to decrypt; empty means all encrypted values