Add a see-also for neighbor query class to their neighborhood structure

Classification/include/CGAL/Classification/Mesh_neighborhood.h

@@ -87,6 +87,8 @@ public:
     Functor that computes the 1-ring neighborhood of the face of an input mesh.
 
     \cgalModels CGAL::Classification::NeighborQuery
+
+    \sa Mesh_neighborhood
   */
   class One_ring_neighbor_query
   {
@@ -118,6 +120,8 @@ public:
     Functor that computes the N-ring neighborhood of the face of an input mesh.
 
     \cgalModels CGAL::Classification::NeighborQuery
+
+    \sa Mesh_neighborhood
   */
   class N_ring_neighbor_query
   {

Classification/include/CGAL/Classification/Point_set_neighborhood.h

@@ -105,6 +105,8 @@ public:
     fixed number of neighbors.
 
     \cgalModels CGAL::Classification::NeighborQuery
+
+    \sa Point_set_neighborhood
   */
   class K_neighbor_query
   {
@@ -138,6 +140,8 @@ public:
     input point.
 
     \cgalModels CGAL::Classification::NeighborQuery
+
+    \sa Point_set_neighborhood
   */
   class Sphere_neighbor_query
   {