Add 3 new type of object: Sphere, Object and Intersect.

Add Intersect object as a way to report where a ray intersect another object and which one it is.
Add an Object base class for all object that can be rendered.
Add the Sphere object.

source/include/sphere.h

@@ -0,0 +1,23 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Sphere header
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#ifndef DORAYME_SPHERE_H
+#define DORAYME_SPHERE_H
+
+#include <object.h>
+#include <ray.h>
+#include <intersect.h>
+
+class Sphere : public Object
+{
+public:
+    /* All sphere are at (0, 0, 0) and radius 1*/
+    virtual Intersect intersect(Ray r);
+};
+
+#endif //DORAYME_SPHERE_H