adds the AS guide to the guides index

railties/guides/source/active_support_core_extensions.textile

@@ -3543,4 +3543,5 @@ h3. Changelog
 
 "Lighthouse ticket":https://rails.lighthouseapp.com/projects/16213/tickets/67
 
+* August 10, 2010: Starts to take shape, added to the index.
 * April 18, 2009: Initial version by "Xavier Noria":credits.html#fxn

railties/guides/source/index.html.erb

@@ -88,6 +88,10 @@ Ruby on Rails Guides
 
 <dl>
 
+<%= guide("Active Support Core Extensions", 'active_support_core_extensions.html') do %>
+  <p>This guide documents the Ruby core extensions defined in Active Support.</p>
+<% end %>
+
 <%= guide("Rails Internationalization API", 'i18n.html') do %>
   <p>This guide covers how to add internationalization to your applications. Your application will be able to translate content to different languages, change pluralization rules, use correct date formats for each country and so on.</p>
 <% end %>

railties/guides/source/layout.html.erb

@@ -62,6 +62,7 @@
             </dl>
             <dl class="R">
               <dt>Digging Deeper</dt>
+              <dd><a href="active_support_core_extensions.html">Active Support Core Extensions</a></dd>
               <dd><a href="i18n.html">Rails Internationalization API</a></dd>
               <dd><a href="action_mailer_basics.html">Action Mailer Basics</a></dd>
               <dd><a href="testing.html">Testing Rails Applications</a></dd>