Add .html suffixes to links.

_includes/menu.html

@@ -1,10 +1,10 @@
         <h1><a href="/">DataMapper</a></h1>
 
         <ul>
-          <li><a href="/community">Community</a></li>
+          <li><a href="/community.html">Community</a></li>
           <li><a href="/docs/">Documentation</a></li>
           <li><a href="/development/">Development</a></li>
-          <li><a href="/contribute">Contribute</a></li>
+          <li><a href="/contribute/">Contribute</a></li>
           <li><a href="http://wiki.github.com/datamapper/dm-core">Wiki</a></li>
-          <li><a href="/getting-started" id="getStarted">Get Started</a></li>
+          <li><a href="/getting-started.html" id="getStarted">Get Started</a></li>
         </ul>

index.html

@@ -12,7 +12,7 @@
 
 <p class="blurb">
 To learn a little more about this project and why you should be interested,<br>
-read the <a href="/why">Why Datamapper?</a> page.
+read the <a href="/why.html">Why Datamapper?</a> page.
 </p>
 
 <h2 class="latest-release">Recent News</h2>
@@ -31,7 +31,7 @@ <h2>Help</h2>
   If you're having trouble, don't forget to check the documentation, which
   has both references and step by step tutorials.
 
-  <p><a href="/docs">Read documentation</a></p>
+  <p><a href="/docs/">Read documentation</a></p>
 </div>
 
 <div id="bugs">