fixed typo

Author: dstine

index.html

@@ -15,7 +15,7 @@ <h2>Introduction to the Git Reference</h2>
     <p>
     Each section will link to the next section, so it can be used
     as a tutorial.  Every page will also link to more in-depth
-    Git documentation such as the offical manual pages and relevant
+    Git documentation such as the official manual pages and relevant
     sections in the <a href="http://progit.org">Pro Git book</a>, 
     so you can learn more about any of 
     the commands. First, we'll start with thinking about source code