Need to bring API docstrings into the docs

## Motivation

Desire to fully document pyfvcom2's API.

## Approach

* Investigate available tools for doing this (e.g., from sphinx) and implement the one best suited to the project, balancing simplicity, ease of maintenance and the quality of the documentation produced.
* Ensure consistent docstring formatting and depth throughout the project (copilot should be able to help here).
