Added an index file to doxygen to interlink modules.

Documentation/Doxygen/Physics2D.doxygen

@@ -619,7 +619,7 @@ WARN_LOGFILE           =
 # directories like "/usr/src/myproject". Separate the files or directories 
 # with spaces.
 
-INPUT                  = ../../Modules/Contents/2DPhysics
+INPUT                  = ../../Modules/Contents/2DPhysics  index.dox
 
 # This tag can be used to specify the character encoding of the source files 
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is 

Documentation/Doxygen/Physics3D.doxygen

@@ -619,7 +619,7 @@ WARN_LOGFILE           =
 # directories like "/usr/src/myproject". Separate the files or directories 
 # with spaces.
 
-INPUT                  = ../../Modules/Contents/3DPhysics
+INPUT                  = ../../Modules/Contents/3DPhysics index.dox
 
 # This tag can be used to specify the character encoding of the source files 
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is 

Documentation/Doxygen/Polycode.doxygen

@@ -619,7 +619,7 @@ WARN_LOGFILE           =
 # directories like "/usr/src/myproject". Separate the files or directories 
 # with spaces.
 
-INPUT                  = ../../Core/Contents
+INPUT                  = ../../Core/Contents index.dox
 
 # This tag can be used to specify the character encoding of the source files 
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is 

Documentation/Doxygen/Polycode_ui.doxygen

@@ -619,7 +619,7 @@ WARN_LOGFILE           =
 # directories like "/usr/src/myproject". Separate the files or directories 
 # with spaces.
 
-INPUT                  = ../../Modules/Contents/UI
+INPUT                  = ../../Modules/Contents/UI index.dox
 
 # This tag can be used to specify the character encoding of the source files 
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is 

Documentation/Doxygen/index.dox

@@ -0,0 +1,12 @@
+// This file defines the index page for the doxygen documentation generated.
+
+/**
+\mainpage Polycode
+
+\section Modules
+<a href="../../Polycode/html/index.html">Core</a> <br>
+<a href="../../PolycodeUI/html/index.html">UI Module</a> <br> 
+<a href="../../Physics2D/html/index.html">Physics2D</a> <br>
+<a href="../../Physics3D/html/index.html">Physics3D</a> <br>
+
+*/