> Some basic requirements are: - searchable - code snippets - hyperlinking

I think another requirement to add is diagramming. I think wiki-style diagramming would be a big help for programmers to better communicate ideas.

I've used external tools like draw.io but the overhead for editing, downloading, and uploading I feel gets in the way. Sadly, we are on confluence but don't use the draw.io plugin [1]. Built-in support for dot, uml, or even ascii diagrams [2] would be big help.

[1] https://about.draw.io/integrations/confluence-integration-2/

[2] e.g. https://github.com/ivanceras/svgbob