Fix warnings in Antora docs build logs

Summary

There are several low-priority warnings in the console log whenever the docs site is built (see here); this task is for fixing them!

Background

These warnings do not break the pipeline, but they are indicators of possible breakage in the future. It is a good idea to fix these as we go instead of letting them pile on. This is also an activity that can be great for a new contributor who wants to learn more about how our documentation pipeline works. Therefore, this issue is labeled as good first issue and should be reserved for newcomer contributors.

Details

The best place to look is this recent log from a site build in our CI pipeline. However, it is still a good idea to clone this repo locally, build the docs site locally using the provided documentation, and confirm if the errors appear in the local console log.

If yes, then proceed on fixing as many warnings as you can. Whether you can fix one, a few, or all of them, contributions of all sizes are welcome. This issue should remain open as long as there are still warnings in the console, or at least until we can fix all of them that we can without bigger architectural changes.

Outcome

• Increased probability that the docs site content will be future-proofed with changes to Antora.
• A great opportunity for a newcomer to learn more about Fedora Docs, how the pipeline works, and make a useful contribution while learning.