add project-wide documentation

[MasterMedo]

Add project wide documentation explaining the intricacies of the logic.

[basil08]

Is the label a sarcastic take on people refraining from documenting their code?

[MasterMedo]

Haha no, please document your code. This is an issue for me not to forget to create module documentation for the various files in the repository. 😂

On the other hand, I have to create docs pages (github wiki / readthedocs / gitbook).