A quick-ish post buy Eric Holscher, of [Read the Docs][rtd]. [I agree with all of this, therefore I am linking to it.][link] tl;dr: Have a website, not a directory of text files. Use prose, not auto-generated bullshit. Use permalinks. Have the language and version # in your URLs. Keep docs keyed to version #s.
[link]: http://ericholscher.com/blog/2014/feb/27/how-i-judge-documentation-quality/ “How I Judge the Quality of Documentation in 30 Seconds — Surfing in Kansas”
[rtd]: http://readthedocs.org “Read the Docs”