There are so many methods of installing Moodle. In your particular example the shell script is an exact documentation of one such method.
Why not? Documentation is always good!
Why not? Documentation is always good!
Only thing, this is a system admin topic, not a developer topic. So Installing and upgrading help forum would be more suitable. Or, of course, you can add a Moodle Docs page or publish in your own blog, or host the Git repo, ...