Include info about scalability and performance

[kafitzgerald]

Scalability and performance are often important considerations for Earth system science applications (e.g. with high resolution model simulations, ensembles, satellite data, etc.) and frequently something folks ask about with respect to transitioning from NCL to Python. It'd be good to consider these aspects as we build out this resource.

There are a lot of potential ways we could approach this (some more time and resource intensive than others) so I wanted to open this discussion here as a place for conversation around the topic.

As a start, I think acknowledging differences in the text of NCL and Python entries (e.g. with math vs numpy functions) is something we could easily do.