ImGui Version

Hello,

Which version of ImGui was it used in this project?

I am following the steps, provide in the README, to compile the project and I am getting some errors compiling ImGui.

**COMPILATION STEPS**
``` bash
mkdir root
cd root
git clone https://github.com/epezent/implot_demos
git clone https://github.com/epezent/implot
git clone https://github.com/ocornut/imgui
```

**ERRORS:**

Maybe we can update the compile steps forcing the clone of ImGui with the correct version.

Start with the README compilation steps and compare the ImGui revision they currently clone with the version expected by this project; use the reported compiler errors to identify the compatibility issue. Done means the README names or pins the compatible ImGui version and the documented steps build successfully.

Written by the indexing model from the issue text.