Update docs/overview/index.md

Co-authored-by: Steve Piercy <[email protected]>

Author: fredvd

docs/overview/index.md

@@ -72,7 +72,7 @@ Plone is easy to set up compared to other CMSs in its category, extremely flexib
 ## High Level Overview for Developers
 
 Plone is a content management platform with its backend written in Python.
-It is built on top of the open-source Zope web application server and development system. 
+It is built on top of the open source Zope web application server and development system. 
 Plone is making use of the pluggable Zope Component Architecture (ZCA) to provide a highly modular and extensible system.
 Up until version 6, Plone has used server-side rendering to generate HTML-based content, with advanced resource management features for adding and bundling CSS and JavaScript. 
 Additionally, Plone's use of the ZCA makes it easy to extend and custosize, allowing users to create unique, feature-rich websites that are tailored to their specific needs.