Use H1 for the main heading.

Change-Id: I460b320419a43842cf1bd2cd398862f6a2c2dab9

handbook/index.php

diff --git a/handbook/index.php b/handbook/index.php
index 2cfc583..73f019f 100644
--- a/handbook/index.php
+++ b/handbook/index.php
@@ -26,7 +26,7 @@
 <link rel="stylesheet" href="/projects/handbook/resources/handbook.css"/>
 
 <div id="maincontent">
-	<h2>Eclipse Foundation Project Handbook</h2>
+	<h1>Eclipse Foundation Project Handbook</h1>
 	<?php include "./eclipse.html"; ?>
 </div>