Fix typo (#473)

Co-authored-by: Matt Wang <matt@matthewwang.me>

index.md

@@ -53,7 +53,7 @@ remote_theme: just-the-docs/just-the-docs
   $ bundle exec just-the-docs rake search:init
   ```
 
-3. Run you local Jekyll server
+3. Run your local Jekyll server
   ```bash
   $ jekyll serve
   ```
@@ -62,6 +62,7 @@ remote_theme: just-the-docs/just-the-docs
   $ 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.