Fix missing docs group of ext 21

diff --git a/incl/rrtext.hh b/incl/rrtext.hh
index a10c1507754b528c008b5c8ee88db742c5975cb1..b20d1af0bda5e5605d272b75b55ab91868407693 100644 (file)
--- a/incl/rrtext.hh
+++ b/incl/rrtext.hh
@@ -40,6 +40,7 @@ namespace rrts {
 
 /*! \brief Collision check based on enlarged occupancy grid.
  *
+ * \ingroup ext-col
  */
 class RRTExt21 : public virtual RRTS {
 private: