Create supported-fonts.mdx

[kathayl]

Summary

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 documentation style guide has been adhered to.
• If a larger change - such as adding a new page- an issue has been opened in relation to any incorrect or out of date information that this PR fixes.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/docs/browser-rendering/	@mchenco, @cloudflare/pcx-technical-writing, @celso, @danielgek, @kathayl, @ToriLindsay

[github-actions]

Preview URL: https://fe221a73.preview.developers.cloudflare.com
Preview Branch URL: https://kathayl-patch-9.preview.developers.cloudflare.com

Files with changes (up to 15)

Original Link	Updated Link
https://developers.cloudflare.com/browser-rendering/reference/supported-fonts/	https://kathayl-patch-9.preview.developers.cloudflare.com/browser-rendering/reference/supported-fonts/

[ToriLindsay]

Since these notes aren't extensive and they're easy to miss, I'd suggest maybe just adding them to the top under the intro (without any notes header). Just as another paragraph, directly below the intro paragraph. Up to you.