Email 2FA changelog

[jhutchings1]

Summary

This PR adds a changelog for email 2FA.

Screenshots (optional)

Documentation checklist

• Is there a changelog entry (guidelines)? If you don't add one for something awesome and new (however small) — how will our customers find out? Changelogs are automatically posted to RSS feeds, the Discord, and X.
• The change adheres to the documentation style guide.
• If a larger change - such as adding a new page- an issue has been opened in relation to any incorrect or out of date information that this PR fixes.
• Files which have changed name or location have been allocated redirects.

[github-actions]

This pull request requires reviews from CODEOWNERS as it changes files that match the following patterns:

Pattern	Owners
/src/content/changelog/	@cloudflare/pm-changelogs, @cloudflare/pcx-technical-writing

[jhutchings1]

Created this one as a draft because we've got a screenshot which we will add before merging this.

[github-actions]

Preview URL: https://e1d31ecb.preview.developers.cloudflare.com
Preview Branch URL: https://email-2fa.preview.developers.cloudflare.com

Files with changes (up to 15)

Original Link	Updated Link
https://developers.cloudflare.com/changelog/2025-10-30-email-2fa/	https://email-2fa.preview.developers.cloudflare.com/changelog/2025-10-30-email-2fa/

[jhutchings1]

I'm not going to include the screenshot on this one after all, so marking this as ready for review.