Added basic usage section to the README.
Added basic usage section to the README.

telekomatrix/ruby-ll,ttasanen/ruby-ll,telekomatrix/ruby-ll,ttasanen/ruby-ll,YorickPeterse/ruby-ll,telekomatrix/ruby-ll,YorickPeterse/ruby-ll,YorickPeterse/ruby-ll,YorickPeterse/ruby-ll,ttasanen/ruby-ll,telekomatrix/ruby-ll