Plate markdown preview

[ClassicDarkChocolate]

https://codesandbox.io/s/plate-markdown-preview-x8zkyi-x8zkyi

As the sandbox shows (the codes are copied from official example), The **bold** and *italic* texts are automatically formatted. Where's the part of the code does this? I spent an hour and could not find it anywhere. I know the text gets { bold: true }, but where did it get converted to <strong /> tag?