I’ve FINALLY setup a BookStack instance (trivial, once I sorted out a Let's Encrypt issue) for reference documentation. Find it at https://brain.vandragt.com. The ‘pages’ functionality for Known is pretty weak, and I think Bookstack will give me a good organisational structure by default, rather than hacking around in other systems. The Braindump will help me note down things I learn and collate my snippets.
I'll move my reference documentation from my site into it over time.