Fixed typo in misc/README.txt (#2131)

diff --git a/misc/README.txt b/misc/README.txt
index 70f835c..4bd2745 100644
--- a/misc/README.txt
+++ b/misc/README.txt
@@ -12,7 +12,7 @@
   Font atlas builder/rasterizer using FreeType instead of stb_truetype.
   Benefit from better FreeType rasterization, in particular for small fonts.
 
-misc/natnis/
+misc/natvis/
   Natvis file to describe dear imgui types in the Visual Studio debugger. 
   With this, types like ImVector<> will be displayed nicely in the debugger. 
   You can include this file a Visual Studio project file, or install it in Visual Studio folder.