set refs to core mod

docs/modules/ROOT/pages/jme3.adoc

@@ -7,15 +7,6 @@
 ifdef::env-github,env-browser[:outfilesuffix: .adoc]
 
 
-=== Managing Objects in the 3D Scene Graph
-
-
-
-*  <<jme3/advanced/asset_manager#,Asset Manager>>
-*  <<jme3/advanced/save_and_load#,Saving and Loading Nodes (.J3O Files)>>
-*  <<jme3/advanced/collision_and_intersection#,Collision and Intersection>>
-*  <<jme3/advanced/level_of_detail#,Level of Detail>>
-
 === Animations and Scenes
 
 *  <<jme3/advanced/animation#,Animation>>

docs/modules/core/nav.adoc

@@ -17,3 +17,7 @@
 **** xref:custom_meshes.adoc[Custom Meshes]
 **** xref:scene/shape.adoc[Shape]
 **** xref:3d_models.adoc[3D Models]
+*** xref:asset/asset_manager.adoc[Asset Manager]
+*** xref:export/save_and_load.adoc[Saving and Loading Nodes]
+*** xref:collision/collision_and_intersection.adoc[Collision and Intersection]
+*** xref:scene/control/level_of_detail.adoc[Level of Detail]