docs(eslint): clarify note for no-html-link-for-pages rule

[Prasad2604]

Add clarification that the rule @next/next/no-html-link-for-pages does not currently detect custom pageExtensions (e.g., .mdx, .page.tsx).
Linked to issue #53473 for reference.

For Contributors

Improving Documentation

• Run pnpm prettier-fix to fix formatting issues before opening the PR.
• Read the Docs Contribution Guide to ensure your contribution follows the docs guidelines.

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What?

This PR updates the ESLint rules documentation by adding a clarification note for the rule @next/next/no-html-link-for-pages.
The note explains that the rule does not currently detect pages when using custom pageExtensions (e.g., .mdx, .page.tsx).

Why?

Developers using custom pageExtensions may be confused when the rule does not apply to their setup.
This clarification provides better guidance and links directly to the related issue.

How?

• Updated eslint.mdx to include a blockquote note under the @next/next/no-html-link-for-pages rule.
• Linked to the open GitHub issue for context and tracking.

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Related

Fixes #53473

[ijjk]

Allow CI Workflow Run

• approve CI run for commit: 1d889a5

Note: this should only be enabled once the PR is ready to go and can only be enabled by a maintainer