A wrapper for sha2 library to get hash string with [0-9] & [a-z] & [A-Z] alphabet

Code example

```rust fn main() { let someinput = "some string"; let hashed = prettysha2::sha512::gen(someinput); let randomhash = prettysha2::sha512::genrnd(); println!("{}", hashed); // KMW1haL81kP6KR4vwpQoxRngltgmiEoXIYATz6klwmvmIx62mulnQrHscoAy29k7 println!("{}", random_hash) }

```