initial skeleton for extensions in AS guide, just bootstrapping it ma…

…y change

railties/guides/source/active_support_overview.textile

@@ -9,6 +9,122 @@ By referring to this guide you will learn:
 
 endprologue.
 
+h3. Extensions to +Kernel+
+
+...
+
+h3. Extensions to +Object+
+
+...
+
+h3. Extensions to +Module+
+
+...
+
+h3. Extensions to +Class+
+
+...
+
+h3. Extensions to +NilClass+
+
+...
+
+h3. Extensions to +TrueClass+
+
+...
+
+h3. Extensions to +FalseClass+
+
+...
+
+h3. Extensions to +Symbol+
+
+...
+
+h3. Extensions to +String+
+
+...
+
+h3. Extensions to +Numeric+
+
+...
+
+h3. Extensions to +Integer+
+
+...
+
+h3. Extensions to +Float+
+
+...
+
+h3. Extensions to +BigDecimal+
+
+...
+
+h3. Extensions to +Enumerable+
+
+...
+
+h3. Extensions to +Array+
+
+...
+
+h3. Extensions to +Hash+
+
+...
+
+h3. Extensions to +Range+
+
+...
+
+h3. Extensions to +Proc+
+
+...
+
+h3. Extensions to +Date+
+
+...
+
+h3. Extensions to +DateTime+
+
+...
+
+h3. Extensions to +Time+
+
+...
+
+h3. Extensions to +Process+
+
+...
+
+h3. Extensions to +Pathname+
+
+...
+
+h3. Extensions to +File+
+
+...
+
+h3. Extensions to +Exception+
+
+...
+
+h3. Extensions to +NameError+
+
+...
+
+h3. Extensions to +LoadError+
+
+...
+
+h3. Extensions to +CGI+
+
+...
+
+h3. Extensions to +Benchmark+
+
+...
+
 h3. Changelog
 
 "Lighthouse ticket":https://rails.lighthouseapp.com/projects/16213/tickets/67