Add instructions on viewing locally while editing

README.md

@@ -7,3 +7,13 @@ fork of that GitHub repo and maintains all of the history of that repo.
 Having this repo be a fork might make it easier to update this theme in the
 future if there are changes to the theme with updated version of Ruby, Jekyll,
 GitHub Pages, etc.
+
+To develop on this site, you need to have Ruby and jeykll installed locally
+and to locally inspect changes, you need to run:
+
+```
+$ bundle exec jekyll serve
+```
+
+inside of base git repo dir and then the site can be viewed in your local
+browser at `http:/localhost:4000`.