Markdown Setup in Drupal 8 - mwetmore/discover-drupal GitHub Wiki

Download the markdown and libraries modules

composer require drupal/markdown drupal/libraries

DRUSH

drush en -y markdown libraries

URL

http://discovering-drupal.test/admin/modules#input-filters

Or, via the UI, Extend -> Input Filters

Enable the Markdown module

Go to

http://discovering-drupal.test/admin/modules#other

Enable the Libraries module

Create a libraries folder in the docroot

Download the PHP Markdown library from
https://github.com/michelf/php-markdown/archive/lib.zip Unpack it and place it in the "libraries" directory in Drupal root folder. If it doesn't exist you need to create it.

Configuring the UI

Here's where the Github wiki falls short. You can only link to images. No uploads.