Update docs

src/core/math/aabb.h

@@ -18,6 +18,7 @@ namespace crown
 /// @ingroup Math
 namespace aabb
 {
+	/// Resets the AABB @a b.
 	void reset(AABB& b);
 
 	/// Returns the center of the box @a b.

src/core/math/intersection.h

@@ -9,6 +9,8 @@
 
 namespace crown
 {
+/// @addtogroup Math
+/// @{
 
 /// Returns the distance along ray (from, dir) to intersection point with plane @a p
 /// or -1.0 if no intersection.
@@ -30,4 +32,5 @@ bool plane_3_intersection(const Plane& p1, const Plane& p2, const Plane& p3, Vec
 bool frustum_sphere_intersection(const Frustum& f, const Sphere& s);
 bool frustum_box_intersection(const Frustum& f, const AABB& b);
 
+/// @}
 } // namespace crown

src/core/math/sphere.h

@@ -11,10 +11,16 @@
 
 namespace crown
 {
+
+/// Functions to manipulate Sphere.
+///
+/// @ingroup Math
 namespace sphere
 {
+	/// Resets the sphere @a s.
 	void reset(Sphere& s);
 
+	/// Returns the volume of the sphere @a s.
 	float volume(const Sphere& s);
 
 	/// Adds @a num @a points to the sphere @a s, expanding its bounds if necessary.