feat(seo): add Article structured data

[julien-deramond]

Description

This PR adds some structured data for Open {re}Source articles based on https://developers.google.com/search/docs/appearance/structured-data/article#json-ld.

The result has been tested via https://search.google.com/test/rich-results?utm_campaign=devsite&utm_medium=jsonld&utm_source=article.

The schema is automatically filled out with the basic information from the articles' frontmatter but can be overwritten in the articles' frontmatter itself too if needed in the future.

https://main-branch-openresource-dev-git-main-jd-a-7640e3-open-resource.vercel.app/articles/github-marketplace-social-preview-for-your-github-actions contains for example:

<script type="application/ld+json">{
  "@context": "https://schema.org/",
  "@type": "Article",
  "headline": "GitHub Marketplace: Social Preview for Your GitHub Actions",
  "description": "Learn how to create and add a social preview image to your GitHub repository to have a better rendering when sharing on social media platforms the link of your GitHub Actions on the GitHub Marketplace.'",
  "image": "https://openresource.dev/og-image.png",
  "author": {
    "@type": "Person",
    "name": "Julien Déramond",
    "url": "https://github.com/julien-deramond/"
  },
  "publisher": {
    "@type": "Organization",
    "name": "Open &lcub;re&rcub;Source",
    "url": "https://openresource.dev/",
    "logo": {
      "@type": "ImageObject",
      "url": "https://openresource.dev/android-chrome-192x192.png"
    }
  },
  "datePublished": "2023-09-15",
  "dateModified": "2023-09-18"
}</script>

and other pages don't contain this type of information.

Motivation & Context

This feature will prolly help with the referencing of Open {re}Source articles in Google.

Type of changes

• New feature (non-breaking change which adds functionality)

Checklist

• I have read the contributing guidelines

[vercel]

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Name	Status	Preview	Updated (UTC)
main-branch-openresource-dev	✅ Ready (Inspect)	Visit Preview	Sep 23, 2023 7:51am

[julien-deramond]

This feature has been deployed into production. https://openresource.dev/articles/github-marketplace-social-preview-for-your-github-actions for instance now contains Article structured data that is recognized by Google (tested with https://search.google.com/test/rich-results and the Open {re}Source URL).

See the results: https://search.google.com/test/rich-results/result?id=9Wa3sKrwNIgIPbNQex8RnA