Update README.md

README.md

@@ -54,7 +54,11 @@ DOCUMENTATION
 A draft of the [Definitive Guide](docs/guide/README.md) is available.
 
 API docs and a rendering of the definitive guide are currently
-available at http://stuff.cebe.cc/yii2docs/ (updated four times per hour) and at http://www.yiiframework.com/doc-2.0/guide-index.html.
+available under the following urls:
+
+- http://stuff.cebe.cc/yii2docs/ API and Definitive Guide (updated every 15 minutes from the github source)
+- http://www.yiiframework.com/doc-2.0/guide-index.html API and Definitive Guide (last updated for the beta release)
+- http://stuff.cebe.cc/yii2-guide.pdf The PDF version of the Guide
 
 For 1.1 users, you may refer to [Upgrading from Yii 1.1](docs/guide/intro-upgrade-from-v1.md)
 to have a general idea of what has changed in 2.0.