Add logo, API documentation

Breaking changes:

• None

New features:

• None

Bug fixes / reliability improvements:

• Fix broken "cli" extra - you can now install pip3 install records-mover[cli] and have a working mvrec (#58)

Other updates:

• API documentation published to https://records-mover.readthedocs.io/en/latest/?badge=latest (#98)
• Convert Asana tickets in comments to GitHub issues (#96)
• Fix inaccuracies in README (#74)
• Add extra name for Parquet support (#73)
• Add logo to README (#72)