Update to V1.87

[neclepsio]

This is a pretty big update to work on. Since this update changes the API to send keystrokes from backend to imgui, this requires an API change. Also, this requires changes to backends, for which I'm not planning to make a pull request (I use a custom backend); more information at https://github.com/ocornut/imgui/releases/tag/v1.87.

[dertseha]

Thank you for the initiative. I've only briefly read the release notes before, with the big changes that will have to be another major version increase.

This may have to sit a while, as I again will have to find time for this. Added to that, I would appreciate if someone would also take care of imgui-go-examples project to create a corresponding PR for this as well. I want to avoid a state where this new version cannot be easily showcased.

Adding "help wanted" to this.

[dertseha]

Again, thank you for the initiative. However, this repository is getting archived. If you still want to follow up on updating the version, please refer to the recommended fork https://github.com/eliasdaler/imgui-go .