A trait for serializing values into some nested structured representation that supports
null, bool, numbers, strings, vectors, and maps (e.g. JSON or Protobuf).
Render self into any Format sink. Designed for use by code that wants to expose a
statically typed Rust value (e.g. each field of ProtocolConfig) through one of the
Format-implementing wire types (serde_json::Value, prost_types::Value, etc.) without
having to enumerate the destination type at the call site.