Add copyright text

Author: BlueGradientHorizon

src/main/java/net/wurstclient/hacks/MurderMysteryHack.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) 2014-2024 Wurst-Imperium and contributors.
+ *
+ * This source code is subject to the terms of the GNU General Public
+ * License, version 3. If a copy of the GPL was not distributed with this
+ * file, You can obtain one at: https://www.gnu.org/licenses/gpl-3.0.txt
+ */
 package net.wurstclient.hacks;
 
 import com.mojang.blaze3d.systems.RenderSystem;