Adding More Tests for Keccak

[0xNeshi]

While using this keccak implementation, I've noticed that it is exceptionally low on any kind of tests for such a popular crate.
Was this an intentional decision or tests were just never focused on?

We implemented a bunch of tests in our own repo for a wrapper around tiny-keccak, and we were wondering if the maintainers of this repository would be open to letting us create a PR adding these tests to tiny-keccak directly?