minor #5035 reword to serves (cordoval)

This PR was submitted for the 2.6 branch but it was merged into the 2.3 branch instead (closes #5035).

Discussion
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reword to serves

Commits
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5ef1e08 reword to serves

Author: weaverryan

cookbook/configuration/web_server_configuration.rst

@@ -21,7 +21,7 @@ to use PHP :ref:`with Nginx <web-server-nginx>`.
     static files, including images, stylesheets and JavaScript files. It is
     also where the front controllers live. For more details, see the :ref:`the-web-directory`.
 
-    The web directory services as the document root when configuring your
+    The web directory serves as the document root when configuring your
     web server. In the examples below, the ``web/`` directory will be the
     document root. This directory is ``/var/www/project/web/``.