To see the generated document, do the following steps:
  Local
    1. Install Ruby with the files to build native modules. In Ubuntu, $ sudo apt install ruby-all-dev
    2. Install Ruby's Bundler (https://bundler.io/). In Ubuntu, $ sudo apt install ruby-bundler
    3. $ cd {{{{{markdown_dir_path}}}}}
    4. $ bundle config set --local path '.vendor/bundle'
    5. $ bundle install
    6. $ bundle exec jekyll serve --incremental
    7. Open http://127.0.0.1:4000 on your web browser

  GitHub Actions
    See sample of https://github.com/{{{{{repository}}}}}