A new parallelization lecture was added in QuantEcon/lecture-source-py#719

At the bottom are commented out headings for Dask and GPUs.

These can be added sequentially while the lecture is live, probabily starting with Dask.

@mmcky, I'll leave this up to you, as discussed. The lecture is already listed as co-authored with you. It might be good to read the whole lecture and the ones mentioned within to get a sense of the flow of discussion and know what has already been said.

(The GPU discussion can be put aside if you like but it only needs to be a few lines at this stage, with no example code for obvious reasons.)