Proposal of Layout

[koaning]

This is a PR so that @polm can give a review on the file structure. I tried to split the utilities from the spaCy library into separate files to make it somewhat easier to maintain. My approach is to work on one command at a time, but before doing any serious work it'd be good to get the foundation aligned.

This PR implements the clone command and I was able to run this locally without issue.

python -m weasel clone pipelines/tagger_parser_ud

I haven't added any tests yet, partially because I was wondering if we want to use Github actions (which I believe is free) or something else for that (Azure? I might need help to set that up).

[polm]

Thanks for setting this up, this looks fine to me.

The util code in spaCy is huge, so it makes sense to split it up. This looks like it might be split a little too fine - do we need a _compat file? - but it's a good start and we can make adjustments as we find pain points in actual use.

[koaning]

Grand.

I'll chug along and keep adding features. Once there's a milestone I'll let you know :)