Update Subpage layout documentation

[jonirouAtTalan]

Releases : main, 13.4

[github-actions[bot]]

The backport to 13.4 failed:

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

stderr

``` The previous cherry-pick is now empty, possibly due to conflict resolution. If you wish to commit it anyway, use: git commit --allow-empty Otherwise, please use 'git cherry-pick --skip' ```

stdout

``` On branch backport-276-to-13.4 You are currently cherry-picking commit 9517734. (all conflicts fixed: run "git cherry-pick --continue") (use "git cherry-pick --skip" to skip this patch) (use "git cherry-pick --abort" to cancel the cherry-pick operation) nothing to commit, working tree clean ```

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-13.4 13.4
# Navigate to the new working tree
cd .worktrees/backport-13.4
# Create a new branch
git switch --create backport-276-to-13.4
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 9517734c1d75701dd5d4a48868c8b2a21bb3ab0c,194b5096a79fa2be1ca711c3f8c994b5cbefb88c,8d70c439dffdbc9bc0db465718961a5d43c3905e,8e7b131422f7bb028b5ec57dc52ebb1315e56eaa,1523f9b7fe391a112bb7727bc2aff31f2e7dafd2,76382aae076a11e36b2a9b5179db8b2142eae228,1cadf7ff165e47ad0bd34b1e6cd118321827042c,c1721a9edb0549b8177a88d27076323a4fda6dc8,ce9acd523faf68bdd5de8c4144fd12028ace20d1,1f311376582629fef4ab0a82de3cf63cadc14a8f,b7a8621356b6dc778b912164c911100b5900933e
# Push it to GitHub
git push --set-upstream origin backport-276-to-13.4
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-13.4

Then, create a pull request where the base branch is 13.4 and the compare/head branch is backport-276-to-13.4.