Update the relnotes

git-svn-id: http://root.cern.ch/svn/root/trunk@23909 27541ba8-7e3a-0410-8455-c3a389f83636

html/doc/v520/index.html

@@ -8,4 +8,6 @@ users can implement their own definition of libraries, of where to find sources
 See <a href="http://root.cern.ch/root/html/THtml__THelperBase.html"><tt>THtml::THelperBase</tt></a> for their common base; the derived classes implement customizable functionality.</p>
 
 <p>Some small improvements are THtml's improved <i>Search</i> field in the top box of every page, and the display of methods' signal / menu / etc setting (the new yellow labels in the list of function members).
+Templates mentioned e.g. in sources or comments now get linked.
 All generated pages now show the date of the last source modification and the date when the HTML page was last generated.</p>
+<p>THtml now also documents typedefs to classes on a separate page. This is useful for e.g. TMatrixD, THnSparseF, etc where users might not realize that it is a typedef. Now the page states that it's a typedef and forwards to the documentation of the underlying class.</p>