Get a medium editor clone inside Drupal using https://github.com/daviferreira/medium-editor

Download with composer in module root folder: composer install

If you dont have composer installed, you could install it with: curl -sS https://getcomposer.org/installer | php

Should be straight forward. Two settings is included in the install that could be used.

There are some basics things to make this more useful, like adding image handling.