change to xref

docs/modules/ROOT/nav.adoc

@@ -17,7 +17,7 @@
 *** 3D Graphics Concepts
 **** <<jme3/intermediate/multi-media_asset_pipeline#,Multi-Media Asset Pipeline>>
 **** <<jme3/scenegraph_for_dummies#,Scenegraph for Dummies>>
-**** <<jme3/beginner/hellovector#,Hello Vector>>
+**** xref:tutorials:jme3/beginner/hellovector.adoc[Hello Vector]
 **** <<jme3/terminology#,Terminology>>
 **** <<jme3/intermediate/how_to_use_materials#,How to Use Materials>>
 **** <<jme3/intermediate/transparency_sorting#,Transparency and Sorting>>

docs/modules/ROOT/pages/jme3.adoc

@@ -63,7 +63,7 @@ Now that you understood the basics, let's put it all together. The following int
 
 *  <<jme3/intermediate/multi-media_asset_pipeline#,Multi-Media Asset Pipeline>>
 *  <<jme3/scenegraph_for_dummies#,3D Scene Graph for Dummies>>
-**  <<jme3/beginner/hellovector#,Vector visualization &amp; vector operations>>
+**  xref:tutorials:jme3/beginner/hellovector.adoc[Hello Vector]
 *  <<jme3/terminology#,3D Graphics Terminology>>
 *  <<jme3/intermediate/how_to_use_materials#,How to Use Materials>>
 *  <<jme3/intermediate/transparency_sorting#,Transparency Sorting>>