Ugly: the `scripts` directory contains both Snakemake scripts and executable implementation

[gipert]

This is quite confusing, especially because one can use relative imports in modules that define executables:

from .. import patterns

but these must be turn into absolute imports if the module defines scripts to be used in Snakemake rules:

from legenddataflow import patterns

I think we should keep these two types of modules distinct, let's iterate on the package structure here.

[ggmarshall]

How about we move these out of src and instead have them in a local_scripts folder?