docs: Link to subversion installation notes.

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@1888 44740490-163a-0410-bde0-09ae8108e29a

docs/simplesamlphp-install.txt

@@ -25,7 +25,7 @@ Developement version
 --------------------
 
 This document is about the latest stable version of simpleSAMLphp.
-If you want to install the developement version, look at the instructions for installing simpleSAMLphp from subversion.
+If you want to install the developement version, look at the instructions for [installing simpleSAMLphp from Subversion](http://rnd.feide.no/content/installing-simplesamlphp-subversion).
 
 
 Prerequisites