Updated shape documentation

Docs/Architecture.md

@@ -82,6 +82,7 @@ Each body has a shape attached that determines the collision volume. The followi
 * [TaperedCapsuleShape](@ref TaperedCapsuleShape) - A capsule with different radii at the bottom and top.
 * [CylinderShape](@ref CylinderShape) - A cylinder shape. Note that cylinders are the least stable of all shapes, so use another shape if possible.
 * [ConvexHullShape](@ref ConvexHullShape) - A convex hull defined by a set of points.
+* [TriangleShape](@ref TriangleShape) - A single triangle. Use a MeshShape if you have multiple triangles.
 * [PlaneShape](@ref PlaneShape) - An infinite plane. Negative half space is considered solid.
 * [StaticCompoundShape](@ref StaticCompoundShape) - A shape containing other shapes. This shape is constructed once and cannot be changed afterwards. Child shapes are organized in a tree to speed up collision detection.
 * [MutableCompoundShape](@ref MutableCompoundShape) - A shape containing other shapes. This shape can be constructed/changed at runtime and trades construction time for runtime performance. Child shapes are organized in a list to make modification easy.

README.md

@@ -38,6 +38,7 @@ Why create yet another physics engine? Firstly, it has been a personal learning
 	* Tapered-capsule
 	* Cylinder
 	* Convex hull
+	* Plane
 	* Compound
 	* Mesh (triangle)
 	* Terrain (height field)