nmrsim.discrete documentation errors

[Geoffrey Sametz]

Is your request for a correction to the documentation?
If so, please indicate:

• what the error is

The module docstring only lists the first three models (AB, AB2 and ABX). Also, positional arguments should probably be documented in order of position, but the order of Jax and Jbx for the ABX documentation is reversed.

• where the issue is found (e.g. a specific page/section of the online documentation, or the module/function/class/method containing the docstring in question).

in nmrsim.discrete and in the online documentation generated from it