Gemfile

source 'https://rubygems.org'
gem 'github-pages'
gem 'webrick'
#
gem 'html-proofer'
# gem 'html-proofer' # link-checking:  bundle exec htmlproofer ./_site/ --only-4xx --ignore-empty-alt=true --allow-hash-href=true