Git-authorship

**Documentation**
- Remove alt-text in attempt to render feature image on PyPI

**Fixes**
- Show logs when running via the CLI
- Enable running `git-authorship` CLI directly after a `pip install`

**Maintenance**
- Add setup instructions to CONTRIBUTING.md

**Documentation**
- Include README on PyPI

**Maintenance**
- Document how to publish updates to PyPI

**Maintenance**
- Correctly exclude dependencies unauthorized OSS licenses

Overhauled the project to dramatically improve usability.

**Features**
- Added a CLI: `git-authorship https://github.com/USERNAME/REPOSITORY`
- Target a specific `--branch` or revision
- `--clone-to` a specific location.
- Add CSV export
- Add JSON export

**Maintenance**
- Added extensive unit/end-to-end tests to validate functionality.
- Broke up the single file script into multiple mini modules.

**BREAKING CHANGES**
To make the overhaul more manageable, several features were dropped in this initial release.
- Removed "Author Licensing" feature
- Removed "Pseudonyms" feature

Created a single-file script to analyze git authorship information.