Add reading of RINEX 4 navigation files
More robust finding of RINEX obs files when --use-obs is set
Add type hints to some functions for improved documentation and readability
Improve reading of RINEX obs files
Make labels more transparent and colorful
Update documentation
Add new --format optional argument. Allowed options: pdf, eps, png, svg. Default: pdf
Add new --version / -v optional arguments, show program version and exit
Improve --help / -h message
Improve error handling
Generate PDF files with embedded fonts, ready for journal submission
Improve argument handling
Improve documentation
Add explicit z-order control for cleaner display of labels in multiconstellation files
