Update index.md

Removed a small typo.

docs/extensions/index.md

@@ -50,7 +50,7 @@ To get started with development, one should usually follow the steps in "[Create
 conventions closely resemble those of CiviCRM Core and of CiviCRM-Drupal modules. Module extensions are fully supported in CiviCRM 4.2+.
 
 ### 3. Publish
-The CiviCRM ecosystem is built on the belief that non-profit organizations can serve themselves best by collaborating in development of their data-management applications. As a staff, volunteers, and consultants for non-profit organizations, we can share our new enhancements and extensions -- and build a richer whole for the entire ecosystem.
+The CiviCRM ecosystem is built on the belief that non-profit organizations can serve themselves best by collaborating in development of their data-management applications. As staff, volunteers, and consultants for non-profit organizations, we can share our new enhancements and extensions -- and build a richer whole for the entire ecosystem.
 
 Extension authors may make their extensions available to the larger CiviCRM community by publishing them in the [Extensions Directory](https://civicrm.org/extensions).