Need to explain when you need to have Git installed locally

[apawlik]

We should add a note at the top that if you want to work with the repo locally (such as "Check your changes" or "To clone your new repository, use: git clone -b gh-pages https://github.com/your_username/YYYY-MM-DD-site"). This is confusing for novices who don't have Git experience.

[tracykteal]

Thanks @apawlik. I'm not quite sure what you mean here. Could you suggest a PR?

[apawlik]

This was noted by one of the Instructor Training participants which had a go at setting up a workshop website from the template. It's kind of implicit that Git needs to be installed if you want to run "git clone". May be a good idea to make it explicit. I'll try a PR.