fix(snake.cpp .hpp): first step to extracting tail functions and head movement to just head and tail separately

include/snake.hpp

@@ -23,19 +23,21 @@
  * separate the snake and tail from each other
  * */
 
-struct Snake {
-	Snake(int default_direction, int row, int col);
+struct Head {
+	Head(int default_direction, int row, int col);
 	Point m_head;
 	std::vector<Point> m_tails; 
-	// 1: Down, 2: Up, 3: Left, 4: Right
+	// -1: Left, 1: Right, 2: Down, -2: Up
 	int m_direction;
 	// Adds a new tail to m_tails at { row, col }
 	void create_tail(int row, int col);
 	void get_new_head_point(int tail_index, int direction);
+	void get_new_point(int direction);
 };
 
-// struct Tail {
-//
-// }
+struct Tail {
+	Point m_tail_pos;
+
+};
 
 #endif