After searching through the forums, it appears that MANY, MANY people are having problems with this lesson.
Particularly 4/7, but throughout the whole exercise, and that's because of a lack of instructions and/or an assumption on the user's part.
The problem SPECIFICALLY, is that the website (and associated folder structure) created in the previous lesson (Learning to deploy a static website using Jekyll), doesn't carry over into this one.
To solve this, I'd recommend combining both lessons into one. Alternatively, you could carry over/recreate the folder structure and associated files from the previous lesson. As it is, the first instruction in "Deploy your website to github pages" is :
"In the terminal to the right, open a new tab.
Then, use the cd command to navigate to your site's directory."
As it is, the site's directory does not exist.
Attempted retries give you the option to skip on to the next lesson, which is then impossible, because you're still trying to work from a non-existent/empty directory.
The forums don't help much either, because there are a lot of work-arounds (mkdir personal-website) posted that only include steps for that particular challenge, without recreating the whole jekyll page. Meaning that when you get to the end, and try to commit your changes, there aren't any changes.
The attitude by certain users of these forums doesn't help either.
So, TL;DR: If you're stuck on "Deploy your Website to GitHub Pages", open the instructions for "Create a static website using Jekyll" in a new browser tab, and work through them all first, WITHIN your terminal window for the "Deploy using GitHub" exercise. Once that's completed, you should be able to finish the rest of the steps in the deploy lesson without issue.
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