moved Changelog to the documentation for easy reference on the website

CHANGELOG → doc/changelog.rst

+Changelog
+=========
+
 This changelog references all backward incompatibilities as we introduce them:
 
-* 2011-21-09: `ExtensionInterface` has been renamed to
+* 2011-09-22: `ExtensionInterface` has been renamed to
   `ServiceProviderInterface`. All built-in extensions have been renamed
   accordingly (for instance, `Silex\Extension\TwigExtension` has been renamed
   to `Silex\Provider\TwigServiceProvider`)
 
-* 2011-21-09: The way reusable applications work has changed. The `mount()`
+* 2011-09-22: The way reusable applications work has changed. The `mount()`
   method now takes an instance of `ControllerCollection` instead of an
   `Application` one.
 

doc/index.rst

@@ -12,3 +12,4 @@ Silex
     internals
     contributing
     providers/index
+    changelog
\ No newline at end of file