Added basic features

Assets/Scripts/Contracts/IDamageable.cs

@@ -0,0 +1,14 @@
+public struct DamageData
+{
+    public float oldHealth;
+    public float newHealth;
+    public float damageAmount;
+}
+
+public delegate void DamageEventHandler(DamageData damageData);
+
+public interface IDamageable
+{
+    public event DamageEventHandler OnDamageTaken;
+    void Damage(float damageAmount);
+}

Assets/Scripts/Contracts/IDamageable.cs.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 4ceb72078282f284688bc98969182b04