Revamped testbed

This section lacks a header element introducing it:

Welcome to our website! Here's some introductory text without a proper heading.

This is a sidebar with additional information. But it's not introduced by a heading.

Note: Hard to automatically test/detect (partial automating testing possible?). Requires a human tester or AI to determine if a heading is necessary. However, an automated test can be performed by checking that each section also includes a heading element, such as <h1> or <h2>.