Consider adding `maplibre` as a source and target

[louwers]

The MapLibre project is a FOSS continuation of the source code of Mapbox' client libraries when they got closed-sourced.

The MapLibre Style Specification is backward compatible with the style specification of Mapbox. Consider adding maplibre as a --source and --target.

[KaiVolland]

Yeah that sound like a great idea. We should also enhance the README of the parser itself to make clear that it is also suitable for maplibre.