Implement LobbyServer

LobbyServer/ChatManager.cs

@@ -0,0 +1,19 @@
+using System.Collections.Generic;
+namespace LobbyServer
+{
+    class ChatManager
+    {
+        private List<Message> _messages;
+        public IReadOnlyList<Message> Messages => _messages.AsReadOnly();
+
+        public ChatManager()
+        {
+            _messages = new List<Message>();
+        }
+
+        public void Add(Message message)
+        {
+            _messages.Add(message);
+        }
+    }
+}