chore: Port over to mkdocs

[lsetiawan]

While Jupyter-book is great at rendering jupyter notebooks, I think that we can really benefit moving to material for mkdocs (https://squidfunk.github.io/mkdocs-material/) because

1. There are more community use and support around it, such as various plugins and just overall used heavily in industry. Plugins of interest for us: mkdocs-jupyter. This will still give the ability to render jupyter notebooks.
2. It's overall much prettier: Take the google A2A docs page for example: https://google.github.io/A2A/
3. Jupyterbook is getting a huge overhaul to 2.0 version, while this uses a newer technology, it seems to also be an overhaul and the support mostly comes from jupyter team.
4. Another plugin that might be of interest is the mkdocs-llmstxt