Document mapping of snake_case to lowerCamelCase when validating json The protobuf schema uses snake_case: [time_at_last_encounter](https://github.com/phenopackets/phenopacket-schema/blob/dd70d53b2c1dfd5ab6ac25b1b4b422b7be90a6ae/src/main/proto/phenopackets/schema/v2/core/individual.proto#L33) however, when I run pfx-tools example, the json examples using lowerCamelCase E.g. ```json "subject": { "id": "proband C", "timeAtLastEncounter": { "age": { "iso8601duration": "P27Y" } }, ``` At first I thought this was a bug, but I see it is documented (albeit in the most cursory fashion) in the protobuf docs: https://developers.google.com/protocol-buffers/docs/proto3#json I suspect this is highly non-obvious to non-proto-geeks. Add this here: https://phenopacket-schema.readthedocs.io/en/latest/schema.html