flutter_md: 
    git:
      url: https://github.com/CorvusYe/flutter_md

import 'package:flutter_md/flutter_md.dart';

const text = 
  r"""
# Hope  
This project is from 2022-03-25. Development will be completed in a short time.
  """;
Widget widget = Md.toWidget(text, MdTheme());

Md.namedHandles.putIfAbsent('custom', (content) {
  return Text(context); // Param is coming, just do what you want to do.
});