Adding info about composer repository

[butu]

Adding info that you have to add the composer repository first, before installing sitepackage

[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

``` Auto-merging Documentation/MinimalExample/Index.rst On branch backport-241-to-13.4 You are currently cherry-picking commit 7058e93. (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-241-to-13.4
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 7058e9391c065e35b6795dbc4619b724321ce159
# Push it to GitHub
git push --set-upstream origin backport-241-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-241-to-13.4.

[linawolf]

Preported manually