Update documentation.

[Erebus9456]

from pybulletproofs import zkrp_prove, zkrp_verify

proof1, comm1, _ = zkrp_prove(2022, 32)
proof2, comm2, _ = zkrp_prove(2023, 32)

assert zkrp_verify(proof1, comm1)
assert !zkrp_verify(proof2, comm1)

This gives an error,
if I remove "!" then it gives another error that bitsize is not given by adding "32" in verify 's params, the program runs successfully.