DoxygenLayout.xml: initial customizations

DoxygenLayout.xml

@@ -137,7 +137,7 @@
 
   <!-- Layout definition for a group page -->
   <group>
-    <briefdescription visible="yes"/>
+    <detaileddescription title=""/>
     <groupgraph visible="$GROUP_GRAPHS"/>
     <memberdecl>
       <nestedgroups visible="yes" title=""/>
@@ -160,7 +160,6 @@
       <friends title=""/>
       <membergroups visible="yes"/>
     </memberdecl>
-    <detaileddescription title=""/>
     <memberdef>
       <pagedocs/>
       <inlineclasses title=""/>