More typos in comments (#2738)

imgui.cpp

@@ -638,7 +638,7 @@ CODE
     - In the examples/ bindings, for each graphics API binding we decided on a type that is likely to be a good representation for specifying
       an image from the end-user perspective. This is what the _examples_ rendering functions are using:
 
-         OpenGL:     ImTextureID = GLuint                       (see ImGui_ImplOpenGL3_RenderDrawData() function in imgui_impl_glfw_gl3.cpp)
+         OpenGL:     ImTextureID = GLuint                       (see ImGui_ImplOpenGL3_RenderDrawData() function in imgui_impl_opengl3.cpp)
          DirectX9:   ImTextureID = LPDIRECT3DTEXTURE9           (see ImGui_ImplDX9_RenderDrawData()     function in imgui_impl_dx9.cpp)
          DirectX11:  ImTextureID = ID3D11ShaderResourceView*    (see ImGui_ImplDX11_RenderDrawData()    function in imgui_impl_dx11.cpp)
          DirectX12:  ImTextureID = D3D12_GPU_DESCRIPTOR_HANDLE  (see ImGui_ImplDX12_RenderDrawData()    function in imgui_impl_dx12.cpp)

imgui_demo.cpp

@@ -759,7 +759,7 @@ static void ShowDemoWindowWidgets()
         // Here we are grabbing the font texture because that's the only one we have access to inside the demo code.
         // Remember that ImTextureID is just storage for whatever you want it to be, it is essentially a value that will be passed to the render function inside the ImDrawCmd structure.
         // If you use one of the default imgui_impl_XXXX.cpp renderer, they all have comments at the top of their file to specify what they expect to be stored in ImTextureID.
-        // (for example, the imgui_impl_dx11.cpp renderer expect a 'ID3D11ShaderResourceView*' pointer. The imgui_impl_glfw_gl3.cpp renderer expect a GLuint OpenGL texture identifier etc.)
+        // (for example, the imgui_impl_dx11.cpp renderer expect a 'ID3D11ShaderResourceView*' pointer. The imgui_impl_opengl3.cpp renderer expect a GLuint OpenGL texture identifier etc.)
         // If you decided that ImTextureID = MyEngineTexture*, then you can pass your MyEngineTexture* pointers to ImGui::Image(), and gather width/height through your own functions, etc.
         // Using ShowMetricsWindow() as a "debugger" to inspect the draw data that are being passed to your render will help you debug issues if you are confused about this.
         // Consider using the lower-level ImDrawList::AddImage() API, via ImGui::GetWindowDrawList()->AddImage().