Update installation docs to use tabs for per-OS steps.
Review Request #13000 — Created May 1, 2023 and submitted
This introduces the sphinx-tabs (https://sphinx-tabs.readthedocs.io/)
extension to our docs, which allows us to separate out blocks of content
into named tabs. Those tabs can be kept in sync across different tab
This allows us to easily put The Ubuntu/etc. and RHEL/etc. steps under
their own tabs, simplifying the page content when a person is going
through our steps. When they select a tab for an OS, all other steps
will be updated to show the same tab.
Tab functionality will help as we modernize our installation process for
Read through the docs in both HTML and JSON (for website dosc UI) builds.