[chore] Add prettier to cicd

[thompson-tomo]

Fixes #189

Changes

Prettier now runs as part of cicd pipeline to ensure compliancy of new docs and changes.

Important

Pull requests acceptance are subject to the triage process as described in Issue and PR Triage Management.
PRs that do not follow the guidance above, may be automatically rejected and closed.

Merge requirement checklist

• CONTRIBUTING.md guidelines followed.
• Change log entry added, according to the guidelines in When to add a changelog entry.
  • If your PR does not need a change log, start the PR title with [chore]
• Links to the prototypes or existing instrumentations (when adding or changing conventions)

[chalin]

FYI, this is how we have the Prettier check setup for the website: https://github.com/open-telemetry/opentelemetry.io/blob/main/.github/workflows/check-file.yml (via check:format)

[thompson-tomo]

Thanks for the feedback I have adapted it accordingly & it has improved the output.