Add link to installation instruction.

EMAIL.txt

@@ -23,11 +23,14 @@ What's New
 [Include the content of NEWS.txt here]
 
 
-Download
---------
+Download and Install
+--------------------
 
 You can download Theano from http://pypi.python.org/pypi/Theano.
 
+Installation instructions are available at
+http://http://deeplearning.net/software/theano/install.html.
+
 Description
 -----------