JOSS review, docstrings

[alexsquires]

With regards to the review point:

Functionality documentation: Is the core functionality of the software documented to a satisfactory level (e.g., API method documentation)?

Generally speaking, the level of documentation is good, I just had a couple of points I wanted to clarify.

1. Is there a reason why some functions are given docstrings, and some are not? e.g in taufactor.metrics, triple_phase_boundary has no docstring, but the others do.
2. As you are using sphinx+readthedocs to generate your documentation, would it be possible to generate module-level documentation on the readthedocs site? (Though this is more "nice-to-have")

[isaacsquires]

Thank you for raising this. We have added dosctrings for the missing modules and created API reference for the modules in the docs. This should be resolved by #75

[alexsquires]

Great, thank you!