Fix simple typo: targering -> targeting

README.md

 ### Content Management Systems (CMS)
 *Tools for managing digital content.*
 * [Backdrop](https://backdropcms.org) - A CMS targeting small-to-medium sized business and non-profits (a fork of Drupal).
-* [Concrete5](https://www.concrete5.org/) - A CMS targering users with a minimum of technical skills.
+* [Concrete5](https://www.concrete5.org/) - A CMS targeting users with a minimum of technical skills.
 * [Drupal](https://www.drupal.org) - An enterprise level CMS.
 * [Grav](https://github.com/getgrav/grav) - A modern flat-file CMS.
 * [Joomla](https://www.joomla.org/) - Another leading CMS.