Clean up and expand documentation (PTS-150)
Generate Sphinx documentation (PTS-150)
Generate Sphinx apidoc documentation (PTS-150)
Add file .gitignore (PTB-77)
Add documentation files (PTS-150)
Fix numbered list (PTS-150)
Add module docstrings (PTS-150)
Regenerate Sphinx apidoc documentation (PTS-150)
Move code to directory src (PTB-77)
Update Sphinx documentation (PTS-150)