I don't have a strong opinion about the base format, but one of my strongest technical opinions is that all documentation should be computable - that is, it should be generated by a program that's linked together with the code it's describing. You should reference particular code structures in the docs, and if the docs gets out of date it should break so that you're not lying to the reader about what's going on. Depending on how deep you want to go, you can also interact with the base code a bit in the doc-generator, showing particular input/output results, or show a few records from a DB table, etc.
