feat(Articles): New Article Template & Ship 1st Article

Step 1: What is changing in this MR?

• Creation of a dedicated template for "Articles" pages:

  • It allows up to two levels of dynamic paths (i.e /articles/_dynamic1/_dynamic2)
  • Creation of a dedicated service only for "Articles"

• The template has been built to be localized using field-level localization.

• A first Article (/articles/platform-engineering/how-to-build-a-platform-engineering-initiative-that-drives-business-results/) was built using Contentful and the template:

  • First Article Contentful Entry
  • Content Type for Articles, using field-level localization

Production	Review app
N/A	https://3815-engineer-new-article-template-ship-1st-article.about.gitlab-review.app/articles/platform-engineering/how-to-build-a-platform-engineering-initiative-that-drives-business-results/

Step 2: Ensure that your changes comply with the following, where applicable:

• I, the Assignee, have run Axe tools on any updated pages, and fixed the relevant accessibility issues.
• These changes work on both Safari, Chrome, and Firefox.
• These changes have been reviewed for Visual Quality Assurance and Functional Quality Assurance on Mobile, Desktop, and Tablet.
• These changes work with our Google Analytics and SEO tools.
• These changes have been documented as expected.

Build Variables:

• Use Contentful Preview API

Closes #3815 (closed)