[TASK] Overhaul HMENU root line page

[linawolf]

• Use confvals
• Correct indentation
• Overhaul example

releases: main, 12.4, 11.5

[github-actions]

The backport to 11.5 failed:

The process '/usr/bin/git' failed with exit code 1

stderr

error: could not apply 497df863... [TASK] Overhaul HMENU root line page
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".

stdout

Auto-merging Documentation/ContentObjects/Hmenu/Rootline.rst
CONFLICT (content): Merge conflict in Documentation/ContentObjects/Hmenu/Rootline.rst

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-11.5 11.5
# Navigate to the new working tree
cd .worktrees/backport-11.5
# Create a new branch
git switch --create backport-1177-to-11.5
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 497df86310cd334bcad4ca66cc9a703e73acda75,70b69f6f63441efbf9bc39cb40a1c26f4528e042,845e223c1474b26dbc9d179f9db714e7fefbce92,ba35147cd0988d14b4c71cd49b3d78530534fe27
# Push it to GitHub
git push --set-upstream origin backport-1177-to-11.5
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-11.5

Then, create a pull request where the base branch is 11.5 and the compare/head branch is backport-1177-to-11.5.