Add increased documentation and descriptive variable names

[texloch]

Although the documentation of this project is an improvement from the original Fortran documentation, there is still much left to be desired.

For a model such as this that is often misunderstood or misinterpreted, it is imperative to provide thorough documentation describing not only the purpose of each method, but also the intermediate variables and calculations.

This provides developers, maintainers, and users with a greater ability to explain the model to others (e.g., at a low level to non-technical stakeholders), and to make adjustments as necessary for their specific applications.