serialize method
Implementation
@override
Uint8List serialize(TypstExternalScannerState state) {
final output = BytesBuilder(copy: false);
_serializeVector(output, state.indentation);
_serializeVector(output, state.containers);
output
..addByte(state.immediate ? 1 : 0)
..addByte(state.headingLevel & 0xff)
..addByte(state.lineStart ? 1 : 0);
return output.takeBytes();
}