added folder uploading with their content via upload method #73

[o-200]

Added folder uploading into neocities
My pull request closes the request #71

i don't decided to touch push method just because it already complicated plus currently it main purpose is uploading all entire project. I just dont want to make it dirty.

Added functionality is -

# Upload 'cats' folder on your site
$ neocities upload cats/

# Upload 'cats' folder to the 'images' directory
$ neocities upload -d images cats/' 

[A-Infor]

@o-200 Who is going to evaluate this pull request?

[o-200]

@o-200 Who is going to evaluate this pull request?

Hey! @kyledrake is responsible for evaluate and maintaining of this gem. If I had a responsibility, it would have already been pushed.