Feature/heading inspector - #493

Changed pages include:

• knowledge/web-components/index.html - view
• examples/forms/bad-example/index.html - view
• examples/forms/good-example/index.html - view
• examples/forms/grouping-with-fieldset-legend/index.html - view
• examples/forms/grouping-with-headings/index.html - view
• examples/forms/html-5-validations/index.html - view
• examples/forms/in-tables/index.html - view
• examples/forms/non-interactive-content/index.html - view
• examples/forms/required/index.html - view
• examples/forms/validation-messages/index.html - view

There are more changes not included in the list