fix: usage tracker docs

[javiermolinar]

What this PR does:

There was a bug in the documentation.

The YAML should look like:

myMap:
  key1: value1
  key2: value2

Previously it was:

myMap:
  - key1: value1
  - key2: value2

This is a list of maps: []map[string]string, not a map[string]string.

I have also enabled cost attribution for the docker-compose local example

Checklist

• Tests updated
• Documentation added
• CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX]

[tempo-ci-app]

The backport to release-v2.8 failed:

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

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new branch
git switch --create backport-5356-to-release-v2.8 origin/release-v2.8
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x c656706a096d6cd0ea7aabfcde131a991b6424c0

When the conflicts are resolved, stage and commit the changes:

git add . && git cherry-pick --continue

If you have the GitHub CLI installed:

# Push the branch to GitHub:
git push --set-upstream origin backport-5356-to-release-v2.8
# Create the PR body template
PR_BODY=$(gh pr view 5356 --json body --template 'Backport c656706a096d6cd0ea7aabfcde131a991b6424c0 from #5356{{ "\n\n---\n\n" }}{{ index . "body" }}')
# Create the PR on GitHub
echo "${PR_BODY}" | gh pr create --title '[release-v2.8] fix: usage tracker docs' --body-file - --label 'type/docs' --label 'backport' --base release-v2.8 --milestone release-v2.8 --web

Or, if you don't have the GitHub CLI installed (we recommend you install it!):

# Push the branch to GitHub:
git push --set-upstream origin backport-5356-to-release-v2.8

# Create a pull request where the `base` branch is `release-v2.8` and the `compare`/`head` branch is `backport-5356-to-release-v2.8`.

# Remove the local backport branch
git switch main
git branch -D backport-5356-to-release-v2.8