Examples: GL3: Comments about gl3w (#880)

examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp

@@ -12,7 +12,7 @@
 // SDL,GL3W
 #include <SDL.h>
 #include <SDL_syswm.h>
-#include <GL/gl3w.h>
+#include <GL/gl3w.h>    // This example is using gl3w to access OpenGL functions (because it is small). You may use glew/glad/glLoadGen/etc. whatever already works for you.
 
 // Data
 static double       g_Time = 0.0f;