Expose containerized Admin guide in navigation

[aneta-petrova]

What changes are you introducing?

• Adding Admin guide to the list of containerized guides in navigation (because it now contains containerized backup documentation that we want users to be aware of)
• Removing the guide-not-ready snippet (because the snippet was added as an additional warning for users who might stumble across the guide even though it was not in navigation; that's not needed anymore because the guide will be exposed in navigation intentionally and it will contain containerized documentation intended for user consumption)

Why are you introducing these changes? (Explanation, links to references, issues, etc.)

#4850 will add first new content for the Admin guide and after that, we can add it to navigation.

Anything else to add? (Considerations, potential downsides, alternative solutions you have explored, etc.)

Contributor checklists

• I am okay with my commits getting squashed when you merge this PR.
• I am familiar with the contributing guidelines.

Please cherry-pick my commits into:

• Foreman 3.19/Katello 4.21
• Foreman 3.18/Katello 4.20 (Satellite 6.19)
• Foreman 3.17/Katello 4.19
• Foreman 3.16/Katello 4.18 (Satellite 6.18; orcharhino 7.6, 7.7, and 7.8)
• Foreman 3.15/Katello 4.17
• Foreman 3.14/Katello 4.16 (Satellite 6.17; orcharhino 7.4; orcharhino 7.5)
• We do not accept PRs for Foreman older than 3.14.

[github-actions]

The PR preview for 761f2e7 is available at theforeman-foreman-documentation-preview-pr-4983.surge.sh

The following output files are affected by this PR:

• Administering_Project/index-containerized-katello.html
• Managing_Content/index-foreman-el.html

show diff

show diff as HTML

[aneta-petrova]

Now that #4850 has been merged, we can expose the containerized Admin guide in navigation so that users can get access to the backup docs. Can someone please review?

[jafiala]

Thank you!

[Lennonka]

It might be too early because of a new assembly from #4882
However, we could hide the assembly for containerized for now.

[aneta-petrova]

It might be too early because of a new assembly from #4882 However, we could hide the assembly for containerized for now.

Anything that is not ready for containerization should not be included in ifdef::containerized[] yet. This PR exposes the guide, but the only parts that are included in the containerized preview are certain parts of backup documentation.

[aneta-petrova]

I updated the PR's description with a bit more information on the reasoning behind this PR.