remove links underlying

git-svn-id: http://root.cern.ch/svn/root/trunk@49335 27541ba8-7e3a-0410-8455-c3a389f83636

docbook/primer/css/github.css

@@ -14,6 +14,7 @@ body > *:last-child {
   margin-bottom: 0 !important; }
 
 a {
+  text-decoration: none;
   color: #4183C4; }
 a.absent {
   color: #cc0000; }