Add documentation

[tkilias]

Background

• This project still misses documentation including readme, user guide, ...
• We also miss the automated generation publishing of the documentation from https://github.com/exasol/bucketfs-utils-python

Acceptance Criteria

• [ ] - Add documentation generation and publishing
• [ ] - Add user guide
  • Usage
  • Overview about the training process
• [ ] - Add Readme
• [ ] - Add changelog
• [ ] - Add Developer Guide

[ckunki]

Planned for any of the next cleanup events.