Adding a timer

include/systems/timer_system.h

@@ -0,0 +1,12 @@
+/*
+** EPITECH PROJECT, 2019
+** MUL_my_runner_2019
+** File description:
+** texture_renderer_system
+*/
+
+#pragma once
+
+#include "system.h"
+
+extern const gc_system timer_system;