//! `switchback-protobuf` CLI: parse .proto files into a switchback.
//!
//! switchback-protobuf [--render mdbook] [--no-switchback] <input...>
//!
//! Always emits a switchback binary file unless `--no-switchback` is set. An optional
//! protoc-plugin stdin/stdout entry may be kept as a convenience. This binary
//! parses `.proto` files into a switchback.