This seems a little bit inconsistent. Above, `fileName` returned from `PathUtils.filename` for a file named _.coffee.md_ includes the dot, and here it points to that it is only a marker for hidden files. This is enforced in that you need to use _.coffe.md_ in `languages.json` as a filename and not _coffee.md_. I think the behavior is correct as is, so maybe we could just change the comment... what do you think?