Add copyright notices with REUSE Software

[Ludee]

Summary of the discussion

Add the REUSE Software specification to make the repo licenses machine readable.

Type of change (CHANGELOG.md)

Added

• Add license files to folder LICENSES (#64)
• Add dep5 file for copyright notices (#64)
• Add pre-commit hook for REUSE (#64)
• Add copyright notice to all files (#64)
• Add first version of pyproject.toml (#64)

Removed

• Remove the LICENSE.txt file (#64)

Workflow checklist

Automation

Closes #33

PR-Assignee

• 🐙 Follow the workflow in CONTRIBUTING.md
• 📝 Update the CHANGELOG.md
• 📙 Update the documentation

Reviewer

• 🐙 Follow the Reviewer Guidelines
• 🐙 Provided feedback and show sufficient appreciation for the work done

[Ludee]

error: Multiple top-level packages discovered in a flat-layout: ['LICENSES', 'super_repo'].