Add FishNet network library

Assets/FishNet/Runtime/Managing/Timing/PhysicsMode.cs

@@ -0,0 +1,21 @@
+namespace FishNet.Managing.Timing
+{
+    /// <summary>
+    /// How to simulate physics.
+    /// </summary>
+    public enum PhysicsMode
+    {
+        /// <summary>
+        /// Unity performs physics every FixedUpdate.
+        /// </summary>
+        Unity = 0,
+        /// <summary>
+        /// TimeManager performs physics each tick.
+        /// </summary>
+        TimeManager = 1,
+        /// <summary>
+        /// Physics will be disabled.
+        /// </summary>
+        Disabled = 2
+    }
+}