Convert Reactor.Shared to a source-only nuget package

Reactor.Networking.Shared/ModFlags.cs

@@ -0,0 +1,24 @@
+using System;
+
+namespace Reactor.Networking;
+
+[Flags]
+public enum ModFlags : ushort
+{
+    None = 0,
+
+    /// <summary>
+    /// Requires all clients in a lobby to have the mod.
+    /// </summary>
+    RequireOnAllClients = 1 << 0,
+
+    /// <summary>
+    /// Requires the server to have a plugin that handles the mod.
+    /// </summary>
+    RequireOnServer = 1 << 1,
+
+    /// <summary>
+    /// Requires the host of the lobby to have the mod.
+    /// </summary>
+    RequireOnHost = 1 << 2,
+}