Improve Doxygen Documentation (#843)

Docs/Architecture.md

@@ -1,3 +1,5 @@
+[TOC]
+
 # Architecture of Jolt Physics
 
 For demos and videos go to the [Samples](Samples.md) section.

Docs/ReleaseNotes.md

@@ -27,7 +27,7 @@ For breaking API changes see [this document](https://github.com/jrouwe/JoltPhysi
 * Hinge limit constraint forces were clamped wrongly when the hinge was exactly at the minimum limit, making it harder to push the hinge towards the maximum limit.
 * Fixed bug when a body with limited DOFs collides with static. If the resulting contact had an infinite effective mass, we would divide by zero and crash.
 
-# v4.0.2
+## v4.0.2
 
 ### New functionality
 * Support for compiling with ninja on Windows.

Doxyfile

@@ -361,7 +361,7 @@ MARKDOWN_SUPPORT       = YES
 # Minimum value: 0, maximum value: 99, default value: 5.
 # This tag requires that the tag MARKDOWN_SUPPORT is set to YES.
 
-TOC_INCLUDE_HEADINGS   = 0
+TOC_INCLUDE_HEADINGS   = 5
 
 # When enabled doxygen tries to link words that correspond to documented
 # classes, or namespaces to their corresponding documentation. Such a link can