packages and one class in each

core/src/com/mygdx/game/controller/MenuState.java

+package com.mygdx.game.controller;
+
+public class MenuState {
+}

core/src/com/mygdx/game/model/Board.java

+package com.mygdx.game.model;
+
+public class Board {
+}

core/src/com/mygdx/game/view/MenuView.java

+package com.mygdx.game.view;
+
+public class MenuView {
+}