fix: Print the blog cards of the listing as second level headings

Problem/Motivation

The blog listing prints its own h1, and the teaser cards are h3, so the heading order skips a level. Axe reports this as a heading hierarchy problem.

Steps to reproduce

1. Visit the Web Blog listing page.
2. Run an accessibility scan (axe) on the page.
3. See the heading order violation: h1 followed by h3 on the teaser cards, skipping h2.

Proposed resolution

Set the card heading level to 2 in the Web Blog teaser display of the template.

Remaining tasks

• ✅ File an issue about this project
• ❌ Addition/Change/Update/Fix to this project
• ❌ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ➖ Developer Documentation support on feature change/addition
• ➖ User Guide Documentation support on feature change/addition
• ➖ UX/UI designer responsibilities
• ❌ Accessibility and Readability
• ❌ Reviewed by a human
• ❌ Code review by maintainers
• ❌ Full testing and approval
• ❌ Credit contributors
• ❌ Review with the product owner
• ❌ Update Release Notes
• ❌ Release

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

AI-Generated: Yes