Deprecated Examples in Generate Random Values

[fEst1ck]

A few examples in chapter "Generate Random Values" using rand is deprecated.

rust-cookbook/src/algorithms/randomness/rand.md

Line 17 in 5234849

let n1: u8 = rng.gen();

The method is renamed to random; similar for gen_range, which is renamed to random_range.

See https://docs.rs/rand/latest/rand/trait.Rng.html#method.gen.

I've not contributed to this project, but this seems an easy fix and I could open an PR to fix this if wanted :)

[fEst1ck]

Just noticed this should be solved by #726