update RooFit release notes

git-svn-id: http://root.cern.ch/svn/root/trunk@34139 27541ba8-7e3a-0410-8455-c3a389f83636

roofit/doc/v528/index.html

@@ -3,6 +3,10 @@
 <a name="roofit"></a> 
 <h3>RooFit</h3>
 
+<ul>
+<li>Assorted small bug fixes have been applied. No major new features have been introduced since 5.26
+</ul>
+
 <a name="roostats"></a> 
 <h3>RooStats</h3>