Sometimes, you want chit-chat with your readers. Drupal 8 has comment feature but I think it is very simple, not good for real world. So, I have just installed a module for commenting, it named Disqus.
Step by step
1. Register an account at disqus.com
2. Login into Admin Dashboard of your Drupal, and go to admin/modules/install
3. Paste https://ftp.drupal.org/files/projects/disqus-8.x-1.0-rc3.tar.gz into Install from a URL text box and click Install button.