Why stop at `git clone`? Why not include `apt install git` and equivalents for all OSs?
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.
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.
Whenever I write documentation, my first step is to explain how silicon can be used as a transistor.