remove dead link

docs/modules/core/pages/terrain/terrain.adoc

@@ -26,7 +26,6 @@ TerraMonkey is a GeoMipMapping quad tree of terrain tiles that supports real tim
 *  GeoMipMapping: LodControl optimizes the level of detail
 *  Terrain can be randomized or generated from a heightmap
 *  jMonkeyEngine SDK terrain editor
-*  Streaming xref:jme3/advanced/endless_terraingrid.adoc[terrain grid] (i.e. infinite terrain)
 
 
 === Planned Features: