Add live example to webhook-payload-snippet and align with endpoint-schema-snippet

[fern-api]

Summary

Addresses the Slack feedback to add a live example to the Webhook payload snippet component page and align its structure with other component pages — using Endpoint schema snippet as the reference.

Changes

• fern/products/docs/pages/component-library/default-components/webhook-payload-snippet.mdx
  • Replaced the stub intro with a description that mirrors the <EndpointSchemaSnippet> page (what the component does + cross-reference to the related component).
  • Usage section now renders a live <WebhookPayloadSnippet webhook="on-conversation-completed" /> inside a highlight-frame, followed by the corresponding jsx Markdown code block.
  • Expanded the webhook <ParamField> description with the namespace-prefixing note used on the other API-reference snippet pages.
  • Page structure is now: intro → Usage → Properties (matching the snippet component pages, which omit Variants when the component has no additional selectors).
• fern/apis/fai/openapi.json — Added an on-conversation-completed webhook under the new top-level webhooks key so the live snippet has a real payload to render (operationId: on-conversation-completed, tag: Scribe webhooks).
• fern/products/docs/docs.yml — Hid the scribeWebhooks tag from the Scribe API navigation so the docs-only webhook doesn't appear as a customer-facing API page.

Review & Testing Checklist for Human

• Open the preview link and confirm the Usage section renders the live webhook payload (event / conversationId / domain / messageCount / completedAt fields with their example values).
• Confirm the page structure (intro → Usage → Properties) reads consistently with Endpoint schema snippet and Endpoint request snippet.
• Verify the new Scribe webhooks tag does not appear in the Scribe API navigation (it is hidden via scribeWebhooks: hidden: true in docs.yml).

Notes

Requested by: Fern Support

[github-actions]

🌿 Preview your docs: https://fern-preview-fern-webhook-payload-snippet-live-example.docs.buildwithfern.com/learn

Here are the markdown pages you've updated:

• learn/docs/writing-content/components/webhook-payload-snippet