The output of the CLI installer is kind of lame:
... Creating administrator user account done Creating main page with default content done
We can do much better than that. Like after the final done we could have:
MediaWiki has been successfully installed. You can now visit <$URL> to view your wiki. If you have questions, check out our frequently asked questions list: <https://www.mediawiki.org/wiki/Manual:FAQ> or use one of the support forums linked on that page.
I'll mentor this for GCI. This should probably be added in maintenance/install.php in MediaWiki core.