There is krohnkite but I recently read development was halted and there was a new more favourable one. I've bookmarked it somewhere but I'll check!

Edit: this is the one: https://github.com/Bismuth-Forge/bismuth

There's also kwin-tiling https://github.com/kwin-scripts/kwin-tiling

Not sure which is best tbh. I have yet to try them