added config plugin

ConfigPlugin/Config.cs

@@ -0,0 +1,24 @@
+using Newtonsoft.Json;
+
+namespace ConfigPlugin;
+
+public class Config
+{
+    public string? CustomMessage;
+    public string? Player;
+    
+    public void Write()
+    {
+        File.WriteAllText(ConfigPlugin.ConfigPath, JsonConvert.SerializeObject(this, Formatting.Indented));
+    }
+
+    public static Config? Read()
+    {
+        if (!File.Exists(ConfigPlugin.ConfigPath))
+        {
+            return new Config();
+        }
+        
+        return JsonConvert.DeserializeObject<Config>(File.ReadAllText(ConfigPlugin.ConfigPath));
+    }
+}