Added high-level diagrams

[ivanmilevtues]

This PR adds an architectural diagram of the redun codebase, generated through static analysis and LLM-based tools. You can preview how it renders here:
https://github.com/CodeBoarding/GeneratedOnBoardings/blob/main/redun/on_boarding.md

The goal is to give new contributors a fast, intuitive overview of the project's structure and how its core components interact. Since redun already makes great use of diagrams I think that you'd like this approach. Let me know where do you stand on diagram first documentation!

Any feedback is more than welcome!

If it’s helpful, I’d be happy to integrate our free GitHub Action to keep it updated in your Sphinx docs.

Full disclosure: we're trying to turn this into a startup, but we're still in a very early stage and figuring out what will actually be useful for people.

[ivanmilevtues]

Hey, a quick update on our side, this week we released our diagram generaiton engine as an open-source project! If you are interested to see more on how the generation works you can do so at https://github.com/CodeBoarding/CodeBoarding