Examples: Titles/comments in headers

examples/imgui_impl_opengl2.cpp

@@ -1,5 +1,8 @@
+// ImGui Renderer for: OpenGL2 (legacy OpenGL, fixed pipeline)
+// This needs to be used along with a Platform Binding (e.g. GLFW, SDL, Win32, custom..)
+
 // **DO NOT USE THIS CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)**
-// **Prefer using the code in the opengl3_example/ folder**
+// **Prefer using the code in imgui_impl_opengl3.cpp**
 // This code is mostly provided as a reference to learn how ImGui integration works, because it is shorter to read.
 // If your code is using GL3+ context or any semi modern OpenGL calls, using this is likely to make everything more
 // complicated, will require your code to reset every single OpenGL attributes to their initial state, and might