We'll create fresh WordPress site with Mark It Down WordPress! installed. You have 20 minutes to test the plugin after that site we'll be deleted.
This is a simple plugin to help you write posts or pages in plain-text Markdown syntax. And even allowing plaint-text Markdown for comments as well. It will also switch-off the Visual Editor, as you don’t need distractions. This plugin sits on top of a giant’s shoulder, namely Jetpack.
This plugin is also installable via composer, see: https://github.com/7php/MarkItDownWordpress