conformsTo:
http://www.opengis.net/spec/ogcapi-features-1/1.0/conf/core
http://www.opengis.net/spec/ogcapi-features-1/1.0/conf/oas30
http://www.opengis.net/spec/ogcapi-features-1/1.0/conf/html
http://www.opengis.net/spec/ogcapi-features-1/1.0/conf/geojson
http://www.opengis.net/spec/ogcapi-features-2/1.0/conf/crs