Comments tweak (#1231)

imgui.h

@@ -1154,7 +1154,7 @@ struct ImDrawVert
 // You can override the vertex format layout by defining IMGUI_OVERRIDE_DRAWVERT_STRUCT_LAYOUT in imconfig.h
 // The code expect ImVec2 pos (8 bytes), ImVec2 uv (8 bytes), ImU32 col (4 bytes), but you can re-order them or add other fields as needed to simplify integration in your engine.
 // The type has to be described within the macro (you can either declare the struct or use a typedef)
-// NOTE: IMGUI DOESN'T CLEAR THE STRUCTURE AND DOESN'T CALL A CONSTRUCTOR. IF YOU ADD EXTRA FIELDS (SUCH AS A 'Z' COORDINATES) YOU WILL NEED TO CLEAR THE FIELD DURING RENDER OR TO IGNORE IT. 
+// NOTE: IMGUI DOESN'T CLEAR THE STRUCTURE AND DOESN'T CALL A CONSTRUCTOR SO ANY CUSTOM FIELD WILL BE UNINITIALIZED. IF YOU ADD EXTRA FIELDS (SUCH AS A 'Z' COORDINATES) YOU WILL NEED TO CLEAR THEM DURING RENDER OR TO IGNORE THEM. 
 IMGUI_OVERRIDE_DRAWVERT_STRUCT_LAYOUT;
 #endif