Remove .PT Domains article until TLD is supported

[Pemacaa]

Summary

Removes the .PT Domains support article.

The article was written from CentralNic's NIS2 contact-verification notice for .PT (see https://github.com/dnsimple/dnsimple-app/issues/35511#issuecomment-4784087833). DNSimple does not currently support .PT registration/transfer (product page 404s; dnsimple-tlds#310 is still open), so the Help article was premature.

@juankuquintana tagging you for a quick look since this came from the reseller notice you shared.

Files changed

• content/articles/domains-pt.md — deleted
• categories/tlds.yaml — removed .PT Domains from the TLDs category
• content/articles/what-are-domain-contacts.md — removed the .PT cross-link
• _redirects — send /articles/domains-pt/ to /articles/tlds/

Verification

• No remaining references to domains-pt / .PT Domains in content or categories
• Redirects added for bare path, trailing slash, and index.html
• Deploy preview: old URL returns 301 to /articles/tlds/

Notes / merge order

Can restore this article when .PT is actually enabled.

Checklist

• Branch created from up-to-date main
• Only files related to this task are included
• Frontmatter has title, excerpt, meta, and categories (n/a — article removed)
• Opening paragraph directly answers the article's core question (SEO/GEO) (n/a)
• Cross-links updated (removed stale back-link)
• No smart/curly quotes or special characters from macOS
• Callouts use correct types (n/a)
• Tested locally with rake run

Review

• Second expert tagged for feature/product knowledge (@juankuquintana)