Add recursive navigation tutorial (#7720)
Add recursive navigation tutorial (#7720)

Merge pull request 7720
tillgrallert/jekyll,chrisfinazzo/jekyll,jaybe-jekyll/jekyll,x-way/jekyll,chrisfinazzo/jekyll,Strangehill/jekyll,jaybe-jekyll/jekyll,jekyll/jekyll,ryanshaw/jekyll,tillgrallert/jekyll,fulldecent/jekyll,fulldecent/jekyll,Strangehill/jekyll,chrisfinazzo/jekyll,jekyll/jekyll,yhironaka/yhironaka.github.io,Strangehill/jekyll,chrisfinazzo/jekyll,fulldecent/jekyll,Strangehill/jekyll,x-way/jekyll,jaybe-jekyll/jekyll,fulldecent/jekyll,jaybe-jekyll/jekyll,Strangehill/jekyll,tillgrallert/jekyll,jekyll/jekyll,ryanshaw/jekyll,x-way/jekyll,ryanshaw/jekyll,ryanshaw/jekyll,jekyll/jekyll,x-way/jekyll,tillgrallert/jekyll,tillgrallert/jekyll