Medusa System Added

Read about the medusa system [here](https://nadekobot.readthedocs.io/en/latest/medusa/creating-a-medusa/)

src/NadekoBot/Common/Medusa/Config/MedusaConfig.cs

@@ -0,0 +1,19 @@
+using Cloneable;
+using NadekoBot.Common.Yml;
+
+namespace Nadeko.Medusa;
+
+[Cloneable]
+public sealed partial class MedusaConfig : ICloneable<MedusaConfig>
+{
+    [Comment(@"DO NOT CHANGE")]
+    public int Version { get; set; } = 1;
+    
+    [Comment("List of medusae automatically loaded at startup")]
+    public List<string> Loaded { get; set; }
+
+    public MedusaConfig()
+    {
+        Loaded = new();
+    }
+}