import format from 'markdown-it-chat-formatter'
format('**bold!** __underline!__ *italic*');
// => <strong>bold!</string> <u>underline!</u> <em>italic</em>
or you can use it as a markdown-it plugin
import MarkdownIt from 'markdown-it'
import chatPlugin from 'markdown-it-chat-formatter/plugin'
const md = new MarkdownIt();
md.use(chatPlugin)
md.render('**bold!** __underline!__ *italic*')
// => <strong>bold!</string> <u>underline!</u> <em>italic</em>