Added doc for AbstractCharacter

Assets/Scripts/AbstractCharacter.cs

@@ -3,6 +3,14 @@ using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
+/// <summary>
+/// Provides an abstract class to manage characters.
+/// </summary>
+///
+/// The abstract class takes care of initialization, base characteristics,
+/// managing health, energy and collisions.
+/// Child classes should overwrite Shoot(), Move() and Death() to handle
+/// those actions.
 public abstract class AbstractCharacter : MonoBehaviour
 {
     //