add new module

docs/antora.yml

@@ -6,4 +6,5 @@ nav:
 - modules/ROOT/nav.adoc
 - modules/tutorials/nav.adoc
 - modules/core/nav.adoc
+- modules/physics/nav.adoc
 - modules/sdk/nav.adoc

docs/modules/ROOT/pages/jme3.adoc

@@ -9,8 +9,6 @@ ifdef::env-github,env-browser[:outfilesuffix: .adoc]
 
 === Physics Integration
 
-*  <<jme3/advanced/physics#,Physics: Gravity, Collisions, Forces>>
-*  <<jme3/advanced/bullet_multithreading#,Multi-Threaded Physics>>
 *  <<jme3/advanced/physics_listeners#,Physics Listeners and Collision Detection>>
 *  <<jme3/advanced/hinges_and_joints#,Hinges and Joints>>
 *  <<jme3/advanced/walking_character#,Walking Character>>

docs/modules/physics/nav.adoc

@@ -0,0 +1,2 @@
+* xref:physics.adoc[Physics]
+** xref:bullet_multithreading.adoc[Multi-Threaded Physics]