proposal: switch from papermill to ploomber

[edublancas]

Hi, I noticed you're using papermill for running some notebooks. I'm the author of Ploomber, a framework that allows the creation of notebook-based pipelines. Your current code is iterating over a few parameters and executing a notebook template; ploomber can efficiently parallelize and run all of them at the same time. I'm happy to open a pull request so you can see it's worth switching; let me know!