pyproject.toml: add readme to the dynamic metadata list

[yunjunz]

Description of proposed changes

• pyproject.toml: add readme to the dynamic metadata list, attempting to fix the "Not finding README.md specified in pyprojet.toml" error on PyPI website.

• simulation.iono.py: fix typo

Reminders

• [x] Pass Pre-commit check (green)
• [x] Pass Codacy code review (green)
• [x] Pass Circle CI test (green)