Add player controller, state management, and input handling

- Implemented PlayerController.cs to manage player movement and actions.
- Created PlayerState.cs to track player lives, coins, and key status.
- Added CameraFollow.cs for smooth camera movement following the player.
- Developed Character.cs as an abstract class for character behavior.
- Introduced Enums.cs for defining TreasureType and MapElementType.
- Added IDoor interface for door interactions.
- Created InputActions.cs for handling player input actions.
- Implemented MainMenu.cs for basic menu functionality including play and exit options.

Assets/Scripts/Enemies/EnemySpawner.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class EnemySpawner : MonoBehaviour
+{
+    [SerializeField]
+    private GameObject _prefab;
+
+    [SerializeField]
+    private int _maxCharacters=1;
+
+    [SerializeField]
+    private Transform _spawnPoint;
+
+    private int _respawnTimeout = 4;
+    private float _respawnElementTimer;
+
+    private List<Character> _characters;
+
+    // Start is called before the first frame update
+    private void Start()
+    {
+        if(_spawnPoint==null)
+        {
+            _spawnPoint=gameObject.transform;
+        }
+        _characters=new List<Character>();
+    }
+
+    // Update is called once per frame
+    private void Update()
+    {
+         if(_characters.Count<_maxCharacters)
+        {
+            _respawnElementTimer -= Time.deltaTime;
+            if (_respawnElementTimer <= 0)
+            {
+                _respawnElementTimer = _respawnTimeout;
+                var prefab= Instantiate(_prefab, _spawnPoint.position, _spawnPoint.rotation);
+                var character=prefab.GetComponent<Character>();
+                character.OnCharacterDeath+=OnCharacterDeath;
+                
+                _characters.Add(character);
+            }
+            return;
+        }
+    }
+
+    private void OnCharacterDeath(object sender, EventArgs e)
+    {
+        var character=(sender as Character);
+        character.OnCharacterDeath-=OnCharacterDeath;
+        _characters.Remove(character);
+        Destroy(character.gameObject);
+    }
+}