Update code documentation

[andreaskrath]

Description

There are some parts of the code that do not have extensive and thorough documentation, like:

• Correct and up to date summary
• Parameters explanation
• Exceptions

An example of poor documentation can be seen in the one of the constructors for the Week model.

Resolving this issue would be a large project, as it would involve going through the code base and understanding it thoroughly, before updating the provided descriptions and more.

It is likely that this issue only makes sense to complete after or as part of #326

Possible Suggested Solution

• Update documentation for classes, methods and properties.