fixed a typo
diff --git a/imgui.cpp b/imgui.cpp
index 35e28b0..24cdb4e 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -5887,7 +5887,7 @@
/*
// Copyright (c) 2004, 2005 Tristan Grimmer
-// Permission is hereby granted, GImGui.IO.FreeFn of charge, to any person obtaining a copy
+// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
