docs: update diagram to include contentful pipeline

[daine]

🔗 Linked issue

234

❓ Type of change

• [x] 📖 Documentation (updates to the documentation or readme)

📚 Description

This PR updates the documentation of our infrastructure

📝 Checklist

• [x] I have linked an issue or discussion.

• [x] I have updated the documentation accordingly.

[aws-amplify-ca-central-1[bot]]

This pull request is automatically being deployed by Amplify Hosting (learn more).

Access this pull request here: https://pr-287.d3eik05156ec7t.amplifyapp.com