OKTA-749502 - Update ITP event types doc

[brianduffield-okta]

Description:

• What's changed? As per feedback, made updates to this doc: https://developer.okta.com/docs/reference/api/itp-et/ to update two event type descriptions and add a right-hand nav
• Is this PR related to a Monolith release? n/a

Resolves:

• OKTA-749502

[eng-info-dev-github-bot]

Netlify Preview URL for the changes: https://preview-4964--reverent-murdock-829d24.netlify.app

[brianduffield-okta]

Still awaiting SME sign-off. Shouldn't take long to address your note. Thanks!

[brianduffield-okta]

Sicong Shan approves via Slack