Enumerate categories

The Geocoding API has introduced experimental support for category search, which is analogous to MapKit’s MKLocalSearch/MKLocalSearchRequest API. The Geocoding API doesn’t currently support natural language queries; instead, you specify one of a number of predefined keywords as the query and pointOfInterest as the scope (and typically a focalLocation). An application can present the user with a series of buttons for common categories to search for, similar to the one in Apple’s Maps application.

Category search currently works without any modifications to this library. However, we can improve the feature’s discoverability by providing an enumeration of the supported categories. Since the set of categories is open-ended and subject to change, it’ll need to be an extensible string enumeration, similar to the profile identifiers exposed by MapboxDirections.swift. We should mark this enumeration with the - experimental documentation command until the “Preview” tag is removed from the API documentation.

/cc @frederoni @bsudekum

Beginne damit, das Muster zur Enumeration von Profilbezeichnern in MapboxDirections.swift und MBRouteOptions.h zu überprüfen, und vergleiche es anschließend mit der Dokumentation zur Kategoriesuche der Geocoding API. Als erledigt gilt die Aufgabe, wenn eine erweiterbare Enumeration von Kategoriezeichenfolgen bereitgestellt und mit dem experimentellen Dokumentationsbefehl gekennzeichnet ist, bis die API nicht mehr in Preview ist.