Why stop at `git clone`? Why not include `apt install git` and equivalents for all OSs?
If Windows/MacOS doesn't ship git by default, then yes, that should be included. On Linux, the people who are running Linux From Scratch can probably infer what the problem is.
In my company that comes be default. Also, `git clone` helpfully includes a canonical path to the repository, in case you found the README laying around somewhere.
Otherwise, yes, I would include apt install for the dependencies, which is also incredibly valuable to make explicit. The only tricky part is what package manager to reference.
Whenever I write documentation, my first step is to explain how silicon can be used as a transistor.