[render] todo updated

Author: malomo

vclib/render/todo.md

@@ -22,4 +22,5 @@
   - [ ] Include ImGui??
   - [ ] Draw lines trough shader - Work in progress
   - [ ] check retina resolution on macOS + GLFW
-  - [ ] start integration of ImGUI along GLFW
+  - [ ] start integration of ImGUI along GLFW
+  - [ ] fix trackball bug on Qt implementation (pan after wheel zoom)