What this guy said:

Next you can update your site name, avatar and other options using the _config.yml file in the root of your repository (shown below).

The easiest way to make your first post is to edit this one. Go into /_posts/ and update the Hello World markdown file. For more instructions head over to the Jekyll Now repository on GitHub.

And so it began. Acually it began yesterday, as the work was done on Thursday.