docs: `jekyll serve` restart after changing config
docs: `jekyll serve` restart after changing config

These steps were missing in the Step-by-Step instructions on [jekyllrb.com/docs](https://jekyllrb.com/docs/step-by-step/01-setup/).
ryanshaw/jekyll,tillgrallert/jekyll,Strangehill/jekyll,tillgrallert/jekyll,tillgrallert/jekyll,jaybe-jekyll/jekyll,Strangehill/jekyll,chrisfinazzo/jekyll,x-way/jekyll,jaybe-jekyll/jekyll,jaybe-jekyll/jekyll,Strangehill/jekyll,chrisfinazzo/jekyll,Strangehill/jekyll,yhironaka/yhironaka.github.io,ryanshaw/jekyll,ryanshaw/jekyll,x-way/jekyll,jekyll/jekyll,chrisfinazzo/jekyll,jekyll/jekyll,fulldecent/jekyll,jekyll/jekyll,jekyll/jekyll,Strangehill/jekyll,tillgrallert/jekyll,jaybe-jekyll/jekyll,chrisfinazzo/jekyll,ryanshaw/jekyll,x-way/jekyll,tillgrallert/jekyll,fulldecent/jekyll,fulldecent/jekyll,x-way/jekyll,fulldecent/jekyll