[readme] update `learn more` link

the learn more url as changed, this fix the 404 error

README.rst

@@ -3,4 +3,4 @@ Sample Module Repository
 
 This simple project is an example repo for Python projects.
 
-`Learn more <http://kennethreitz.com/repository-structure-and-python.html>`_.
+`Learn more <http://www.kennethreitz.org/essays/repository-structure-and-python>`_.