Simple config object by String literal.

This is designed for libraries to pass simple configs with just a String.

e.g.

Passing "compression_type=zstd;level=3" instead of Config::Builder::new()::with_level(3).with_type(CompressionType::ZSTD).build().unwrap()?

Passing "bind=0.0.0.0;port=8080" to SocketServer instead of (Option<InetAddress>, Option<u32>) tuple?

Your choice.