In the same vein, docussaurus[0] has been a pleasure to work with (not affiliated in any way). It's snappy, has a solid text interface, the search works etc...
I really enjoyed working with docusaurus. Being able to embed live examples of the described SDK to initialise and play around with was excellent and helped us achieve really fast adoption from other teams in our org.
Can I ask if you were using any plugins or other tools for your SDK docs? We're coming up on a similar need in our own Docusaurus site soon and I'm curious if people use any dedicated methods to format/publish their SDK documentation. (My quest to find "an OpenAPI-esque plugin but for things that aren't REST" hasn't turned up much yet.)
[0]https://docusaurus.io/