* Getting source: Add --depth 1 arguments
The whole commit history isn't needed to compile the engine, which is the context of this docs page, so mention the way to avoid cloning all of it.
Also I've changed the second ``--branch`` argument to ``-b`` so the line wouldn't get out of bounds.
Co-authored-by: Max Hilbrunner <mhilbrunner@users.noreply.github.com>
