Add documentation generation

[nfrechette]

While functions are commented, browsing what they do is a bit awkward. It would be nice if we could generate markdown or html somehow. Perhaps switching to doxygen might work?

[bcampbell]

I've always found most C++ autodoc systems a little too... intrusive. Huge comment blocks, lots of redundant structural detail, pointless and pedantic @param lines...

But I do like the look of cldoc so far. Basically, the format required is just how I'd want a good codebase to be commented anyway. The default output format seems a bit noisy though (I'd like prefer something more like godoc. Example output: https://godoc.org/io). I suspect the namespaces and return-type coercion would lead to extra noise too.. but certainly no worse than doxygen et al.

[nfrechette]

Thanks for the suggestion! The return type coercion is definitely the trickiest part to generate documentation for. I might have to pre-process an intermediate format of the doc generation to make it look good in the end result.

I'll definitely check cldoc out when I get around to it.