Docs/set docs hidden

[clayton-cornell]

PR Description

Set docs to be hidden, not published/indexed.

Which issue(s) this PR fixes

Notes to the Reviewer

PR Checklist

• CHANGELOG.md updated
• Documentation added
• Tests updated
• Config converters updated

[rfratto]

LGTM.

So, this will sync to grafana/website/content/docs/alloy/VERSION/*, and hide individual versions. I still wonder if we need to also add this to the metadata of grafana/website/content/docs/alloy/_index.md too (i.e., what if this change only hides individual versions but not the fact that the section exists)

[rfratto]

One downside of this change: make docs hides everything from you now. If setting this on the _index.md one level above the version folder hides everything too, it might be better since it still allows you to view everything locally.

[clayton-cornell]

Wherever it's set, the topic/content is hidden and the TOC entry for the content is not generated. So if it's set one level deeper into the TOC, you still get nothing on the TOC side. You have to know the URL or click an on-page link to navigate to any topic in the tree.

If we really need to test the local build with TOC navigation, we can remove the flag in the working branch, run make docs, test, and then add it back before pushing.