Change term ‘computations’?

[khaeru]

The dask graph specification uses ‘computation’ for any dict value in the graph. A ‘task’—tuple with a callable first element—is one of four kinds of ‘computation’.

In contrast, genno uses ‘computation’ for callables used as those first elements of tasks. This is a little inconsistent; also it's a long word.

Consider alternatives.

[khaeru]

• ‘operation’, ‘operator’, or ‘op’ — e.g. standard library, Airflow, Dagster, pyam.
• ‘ufunc’ in numpy —however these are lower-level.
• ‘function’ may lead to confusion with ordinary Python.