Feature Request: Generating documentation from a single README.md file

Hi,

First of all, thanks for the great project! It's one of the best tools for generating websites with documentation I've found so far.

I think, it would be nice to have a feature, which allows to generate documentation from a single `README.md` file. I have a few small projects with documentation in a single file and I'd like to keep it like this for now. On the other hand, I'd like to use static to generate website with documentation, but in order to do that, I have to reorganize my documentation. I think, possibility of generating documentation in two ways (from multiple files and from a single file) would be useful.

Regards,
Piotr