Change primitive/permute visbility to pub

[davidnevadoc]

Closes #3

[themighty1]

I had a thought about adding a hazmat crate feature and expose this method as pub only when the feature is enabled. This would prevent any accidental misuse by a casual crate user. I could work on that PR.

But if you guys think that having a feature is an overkill, Im ok to proceed with this approach.

[themighty1]

Hi, I realized that the current API of the gadget already allows the creation of a in-circuit permutation chip. We do it here https://github.com/tlsnotary/tlsn/blob/ad994f364a9a8ee406789ce975d04b779659232e/crates/components/authdecode/authdecode-core/src/backend/halo2/circuit.rs#L506

With that in mind, there is no need for a hazmat flag to allow the user to compute the permutation outside of the circuit.
Could we merge this?