docs(config): show TOML examples in robot.toml reference

The "Examples:" blocks were carried over verbatim from Robot
Framework's CLI help, so they showed --flags instead of TOML.
Add a curated TOML_EXAMPLES map in generate_rf_options.py (with
extend- prefix rewriting for extend-* variants) and regenerate
model.py and config.md.

Author: d-biehl