The article on Git doesn't even cover the basics covered in Atlassian's "Getting started" Git tutorial.

https://www.atlassian.com/git/tutorials/

Then there's the unexplainable lesson estimates, where a tutorial consisting of 3 sections, each comprisiing a dozen paragraphs and couple of commands typed in a terminal, somehow is expected to take 2-3 hours to finish.

Anyone interested in Gi can do much better with a simple google search on Git tutorials. Even wikibooks has better content than this site.