More documentation

[colin-jack]

Looks interesting but I'm thinking the project itself could do with more documentation. For example I'd think a lot of people would want to use markdox to recursively go through a folder generating docs, having all the output files written to a separate directory, and it might be worth documenting how to do things like that.

[cbou]

good idea but I don't have time to do it for the moment. Would be great if someone make a pull request.