No matter how good a documentation architecture is, it doesn't beat having a search bar, hence my suggestion :)

Since you are using Docusaurus, you can easily do that with TypeSense, which is free and open source (they also have a paid offer which can make your life easier for the indexes, and updating the data). You can see what we've done for ours.

Happy to discuss how we set up the TypeSense server, or anything else.