Add jekyll-fontello to plugins (#6757)
Add jekyll-fontello to plugins (#6757)

Merge pull request 6757
getandpost/jekyll.github.io,tillgrallert/jekyll,jaybe-jekyll/jekyll,Strangehill/jekyll,Strangehill/jekyll,tillgrallert/jekyll,jekyll/jekyll,x-way/jekyll,chrisfinazzo/jekyll,jaybe-jekyll/jekyll,tillgrallert/jekyll,ryanshaw/jekyll,fulldecent/jekyll,x-way/jekyll,ryanshaw/jekyll,fulldecent/jekyll,chrisfinazzo/jekyll,jekyll/jekyll,fulldecent/jekyll,ryanshaw/jekyll,Strangehill/jekyll,x-way/jekyll,tillgrallert/jekyll,chrisfinazzo/jekyll,Strangehill/jekyll,jekyll/jekyll,getandpost/jekyll.github.io,ryanshaw/jekyll,jaybe-jekyll/jekyll,x-way/jekyll,chrisfinazzo/jekyll,jekyll/jekyll,jaybe-jekyll/jekyll,getandpost/jekyll.github.io,tillgrallert/jekyll,yhironaka/yhironaka.github.io,Strangehill/jekyll,fulldecent/jekyll