feat: a poly check command

A new command: poetry poly check, that will validate the Polylith workspace.

More details in Pull Request.

fix: poly info and poly diff

Pull Request #36

fix(bug): merge sets with Python 3.8-syntax

Pull Request: #35

fix(bug): poly diff --short

Pull Request #34

fix: align poly diff columns

Pull Request #33

fix: poly info command with better aligned columns

Pull Request #32

fix: support for Python 3.8

Support for Python 3.8 (typings): Pull Request 29 by @Brejkarn

fix: docs typos and poly diff clarifications

• fix: typo in docs about installing Poetry plugins
• fix: clarify poly diff output when there are no brick changes

feat: v1 of Python tools for the Polylith Architecture

docs: Poetry plugin docs and clarifications (#27)

* docs: poetry plugin docs and clarifications

feat: poly info command with the basics

a poetry poly info command with the basic functionality:
count number of projects, bases and components.