Merge pull request just-the-docs#117 from gnarea/gh-pages-local

Explain how to use theme locally with GitHub Pages

Author: pmarsceill

index.md

@@ -58,6 +58,8 @@ $ bundle exec jekyll serve
 ```
 4. Point your web browser to [http://localhost:4000](http://localhost:4000)
 
+If you're hosting your site on GitHub Pages, [set up GitHub Pages and Jekyll locally](https://help.github.com/en/articles/setting-up-your-github-pages-site-locally-with-jekyll) so that you can more easily work in your development environment.
+
 ### Configure Just the Docs
 
 - [See configuration options]({{ site.baseurl }}{% link docs/configuration.md %})