Clarify `bundle config` in Bundler tutorial (#8150)
Clarify `bundle config` in Bundler tutorial (#8150)

Merge pull request 8150
ryanshaw/jekyll,chrisfinazzo/jekyll,jaybe-jekyll/jekyll,ryanshaw/jekyll,jaybe-jekyll/jekyll,jekyll/jekyll,ryanshaw/jekyll,yhironaka/yhironaka.github.io,fulldecent/jekyll,x-way/jekyll,jekyll/jekyll,chrisfinazzo/jekyll,jekyll/jekyll,jaybe-jekyll/jekyll,chrisfinazzo/jekyll,ryanshaw/jekyll,fulldecent/jekyll,fulldecent/jekyll,x-way/jekyll,fulldecent/jekyll,jaybe-jekyll/jekyll,jekyll/jekyll,x-way/jekyll,x-way/jekyll,chrisfinazzo/jekyll