For anyone who is vim-curious, I think this is a cool approach to learning practical uses for vim. The “course” is just a react source file (direct link) with the instructions as comments describing how to modify the various bits of code throughout the file. Even though the file is a react component, examples are largely just as applicable to most programming languages (especially those with c-like syntax) as well as editing regular HTML.
I would suggest though, if you’ve never used vim before that an easier setup to dip your toes in would be to install to the vim extension for vscode (or for Visual Studio).