Jekyll plugin for correct sentence spacing, see https://kronopath.com/blog/the-correct-way-to-do-sentence-spacing/

sentence_spacing.rb

def convert_to_sentence_spacing(content)
  content.gsub(/([.?!][)"]?)  /, '\1 ')
end

Jekyll::Hooks.register :posts, :pre_render do | post |
  if post["sentence_spacing"] then
    post.content = convert_to_sentence_spacing(post.content)
  end
end