[Feature] Improve General Documentation

[ErikBavenstrand]

Is your feature request related to a problem? Please describe.
While the automatically generated documentation from docstrings is useful for understanding the technical details of the mleko library, it is not always sufficient for providing a comprehensive understanding of the library's usage, especially for newcomers. I find it difficult to understand how to use the library in a larger context, such as how different components interact with each other, best practices for using the library, and real-world examples.

Describe the solution you'd like
I propose that we supplement the existing docstring-based documentation with more free text-based documentation. This could include tutorials, how-to guides, explanations of the library's design philosophy, and more detailed descriptions of the library's components. In addition, we should provide more real-world examples of how to use the library to solve common problems in model building.

Describe alternatives you've considered
An alternative solution would be to enhance the docstrings with more detailed examples and usage scenarios. However, this might make the docstrings overly verbose and difficult to navigate. Furthermore, it would not provide a suitable place for the more high-level and conceptual documentation that I propose.

Additional context
Good documentation can significantly lower the barrier to entry for new users and can also serve as a valuable reference for existing users. By providing more comprehensive documentation, we can make the MLEKO library more accessible and easier to use.