add the latest version of "Django by Example"

http://lightbird.net/dbe2/

free-programming-books.md

@@ -831,6 +831,7 @@ See also [TeX](#tex)
 ####Django
 * [Djen of Django](http://agiliq.com/books/djenofdjango/)
 * [Django by Example](http://www.lightbird.net/dbe/)
+* [Django by Example for Django 1.5](http://lightbird.net/dbe2/)
 * [Tango With Django](http://www.tangowithdjango.com/book/)
 * [Deploy Django](http://www.deploydjango.com)