Fixes typo in layouts_dir documentation (#8532)
Fixes typo in layouts_dir documentation (#8532)

Merge pull request 8532
jekyll/jekyll,chrisfinazzo/jekyll,fulldecent/jekyll,x-way/jekyll,fulldecent/jekyll,x-way/jekyll,jekyll/jekyll,fulldecent/jekyll,fulldecent/jekyll,chrisfinazzo/jekyll,x-way/jekyll,jekyll/jekyll,ryanshaw/jekyll,chrisfinazzo/jekyll,ryanshaw/jekyll,x-way/jekyll,ryanshaw/jekyll,jaybe-jekyll/jekyll,jaybe-jekyll/jekyll,jaybe-jekyll/jekyll,jekyll/jekyll,jaybe-jekyll/jekyll,chrisfinazzo/jekyll,ryanshaw/jekyll