Looking for a theme to post online docs

Hi forum,
I’d like a theme to write docs with content beside help reader easy to navigate through.
Pls help me to find a theme look like below theme.
This theme have a navigator with only 2 level. I want some level more.

Thank you.

Maybe if you could show the docs layout you are wanting…?

I use the plugin Tablepress to list our docs, and a custom child page menu linking system for easy access to archived pages.

Good luck,