Remove shorthand imports

[mx-moth]

I have a personal style preference for long hand imports like this.

[sharon-tickell]

Noted - what do you think about making a team style guide that has things like that listed?

[mx-moth]

I support a team style guide! I don't know whether I'd bother putting this in the style guide though. It seems very common to do import xarray as xr / import numpy as np in examples, notebooks, and scripts for some reason. It felt gross in a library. I can't really defend my preference enough to argue for its inclusion in a style guide.