added the mdn_urls now those pages have been added

[dletorey]

Summary

• Added the mdn_url for:
  • :heading
  • :heading()

Related issues

• Content PR 40483 heading selectors content#40649
  • New Content PR 40483 heading selectors content#40784
• BCD PR Add CSS :heading and :heading() selectors #27504
• Firefox Release Note PR added ff release notes for :heading pseudo-classes content#40655

[github-actions]

Tip: Review these changes grouped by change (recommended for most PRs), or grouped by feature (for large PRs).

[caugner]

The correct page should be https://developer.mozilla.org/en-US/docs/Web/CSS/:heading_function, and that one has no BCD table yet, and therefore no BCD frontmatter.

[caugner]

Meanwhile added by #27618.

[caugner]

@dletorey Please note that we have automation that adds mdn_urls when the MDN page references BCD key, so manually adding mdn_urls is generally discouraged. (We should maybe make this explicit somewhere in the README or docs.)

Once you add BCD frontmatter to the :heading_function page, it will automatically be added to BCD data within the next day or so. 😉

So I'm going to close this PR.