Rename Plugins Manual to Plugin Manual

Author: Arnd R. Strube

_includes/header.html

@@ -30,7 +30,7 @@ <h2>CppUTest unit testing and mocking framework for C/C++</h2>
 			        	<li class="divider-vertical"></li>
 				        <li><a href="mocking_manual.html">CppUMock Manual</a></li>
 				        <li class="divider-vertical"></li>
-				        <li><a href="plugins_manual.html">Plugins Manual</a></li>
+				        <li><a href="plugin_manual.html">Plugin Manual</a></li>
 				        <li class="divider-vertical"></li>
 				        <li><a href="stories.html">Platforms stories</a></li>
 				        <li class="divider-vertical"></li>

plugins_manual.markdown plugin_manual.markdownplugins_manual.markdown renamed to plugin_manual.markdown

@@ -1,6 +1,6 @@
 ---
 layout: default
-title: Plugins Manual
+title: Plugin Manual
 ---
 
 ## Table of Content