docs(perf): figure out how to stop re-rendering all jupyter notebooks during mkdocs serve

[p-a-a-a-trick]

mkdocs renders all jupyter notebooks during mkdocs serve, slowing documentation update/checking to a snail's pace. It's tedious. Is there some way to speed it up, have them render concurrently, or allow the user to pick-and-choose if/when notebooks should be re-rendered?

task: speed up mkdocs serve wrt rendering jupyter notebooks