I seem to recall once reading either official docs or maybe a blog post about a way to convert a Jupyter Notebook into a kedro pipeline? Is that a thing? Can't seem to find anything googling, so maybe itw as just a dream.

It was not a dream: https://docs.kedro.org/en/0.17.7/11_tools_integration/02_ipython.html#convert-functions-from-jupyter-notebooks-into-kedro-nodes (However, it was deprecated in 0.18.3, removed in 0.19.0)

the one @Deepyaman Datta links is the automated tool (deprecated and removed)