Enable parallelization for a grid of models

[namurphy]

A use case for this code is the heating of coronal mass ejection plasma. As plasma moves away from the Sun, it will cool due to expansion, but also heat will be added through mechanisms that are not well understood. For a study like this, users would need to run a bunch of different models with different heating parameterizations and rates, and it would be beneficial to be able to run this in parallel.

Two possibilities are to:

• Include parallelization capabilities within the package
• Provide an example notebook of running things in parallel, for example with dask.