add javadoc to overriding mixin

mod-fabric/src/eu/e99/pixelchat/fabric/mixin/ChatScreenMixin.java

@@ -16,6 +16,10 @@ public abstract class ChatScreenMixin extends Screen {
         super(title);
     }
 
+    /**
+     * I override this because it doesn't really make a lot of sense to have 2 mods that perform the same thing when files are dragged in.
+     * If you have issues with this, please contact me.
+     */
     @Override
     public void onFilesDropped(List<Path> paths) {
         for (Path path : paths) {