Enhance docstrings and README documentation

[romainsacchi]

Summary

• add comprehensive Sphinx-style docstrings to the converters and supporting utilities
• refresh the README with accurate installation and usage instructions for both conversion directions

Testing

• pytest

---

Codex Task

[coveralls]

Pull Request Test Coverage Report for Build 19174057301

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 5 unchanged lines in 2 files lost coverage.
• Overall coverage remained the same at 0.0%

---

Files with Coverage Reduction	New Missed Lines	%
brightpath/simaproconverter.py	2	0.0%
brightpath/utils.py	3	0.0%

Totals
Change from base Build 19173875352:	0.0%
Covered Lines:	0
Relevant Lines:	756

---

💛 - Coveralls