Cyril Li

I am pretty sure that the problem lies within `gpx_fields_to_xml` in [gpxfield.py](https://github.com/tkrajina/gpxpy/blob/dev/gpxpy/gpxfield.py#L486), with `value = getattr(instance, gpx_field.name)` being a likely culprit, however I am not familiar with the variables used.

I suppose this is intentional.. read the [raw file](https://github.com/FrameworkComputer/InputModules/blob/main/Electrical/LEDMatrix/LEDMatrix.kicad_pcb ), there isn't any useful data in there :/

Originally I wrote the docs for new features in docs/xml. I just found out about `generate_examples.py`, however I am not sure what configuration `venv/bin/python3` has (it seems to have been...