Move OS-dependent Utilities Into OS Package

UI/Window/RenderConfigWindow.cs

@@ -7,7 +7,7 @@ using ADOFAIRenderer.Core;
 using ADOFAIRenderer.Core.Data;
 using ADOFAIRenderer.Data;
 using ADOFAIRenderer.Localization;
-using ADOFAIRenderer.Util;
+using ADOFAIRenderer.Util.OS;
 using MelonLoader;
 using O5Kit.Control;
 using O5Kit.Core;