Documentation

[janden]

How far do we want to go with this? I don't know if it's worth it to have a full-fledged site lite for Finufft, but something more substantial (like a tutorial or something) than in-code documentation might be a good idea.

[ahbarnett]

I think a examples.md viewable in github will be better than a full readthedocs separate site, which is annoying to set up.

[ahbarnett]

1566aaf made the README better for docs, pointing to docs in the source code, which are decent (and I cleaned up). It's ok for now, but would be better to move (note: not copy, since we want SSOT) to a separate user-facing *.md, remembering to point to it from the source code. I won't close, but it's less urgent now.

[ahbarnett]

9004b26 does the above - decent C++ function docs - apart from no tutorial.