Update index.mdx - Data center protection learning path

[caley-b]

Added an additional use - TEST TEST TEST. DELETE THIS. DO NOT PUSH INTO PRODUCTION.

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• If a larger change - such as adding a new page- an issue has been opened in relation to any incorrect or out of date information that this PR fixes.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/learning-paths/	@cloudflare/pcx-technical-writing

[github-actions]

Preview URL: https://25ddcbdb.preview.developers.cloudflare.com
Preview Branch URL: https://caley-b-patch-1.preview.developers.cloudflare.com

Files with changes (up to 15)

Original Link	Updated Link
https://developers.cloudflare.com/learning-paths/data-center-protection/concepts/	https://caley-b-patch-1.preview.developers.cloudflare.com/learning-paths/data-center-protection/concepts/