You really have to go out of your way to not provide 3., any half-decent documentation generation mechanism, even trivial markdown rendering scripts, will have

You really have to go out of your way to not provide 3., any half-decent documentation generation mechanism, even trivial markdown rendering scripts, will have some sort of support for permalinks. Short of deliberately not versioning your documentation, it's quite difficult to avoid producing working permalinks. Generating reference from source is fine, but it's definitely insufficient. Trying to pick up a library or a framework from reference alone is like learning a language solely from a dictionary. Documentation should at least include some general design and architecture elements, and tutorials or commented examples. Writing accurate documentation mostly requires a thorough understanding of the code, it's one of the least easy things to contribute productively as a newcomer. I'd much rather the developer did not implement some features (which they took the time to list or maybe even sketch out their intentions for in the documentation), and documented what they did implement thoroughly. That's a much better starting point for contribution than a more or less feature-complete project that needs reverse engineering because there is no documentation at all.